2014/10/16 - Amazon DynamoDB - 13 new api methods
The Scan operation returns one or more items and item attributes by accessing every item in the table. To have DynamoDB return fewer items, you can provide a ScanFilter operation.
If the total number of scanned items exceeds the maximum data set size limit of 1 MB, the scan stops and results are returned to the user as a LastEvaluatedKey value to continue the scan in a subsequent operation. The results also include the number of items exceeding the limit. A scan can result in no table data meeting the filter criteria.
The result set is eventually consistent.
By default, Scan operations proceed sequentially; however, for faster performance on large tables, applications can request a parallel Scan operation by specifying the Segment and TotalSegments parameters. For more information, see Parallel Scan in the Amazon DynamoDB Developer Guide .
Request Syntax
client.scan(
TableName='string',
AttributesToGet=[
'string',
],
Limit=123,
Select='ALL_ATTRIBUTES'|'ALL_PROJECTED_ATTRIBUTES'|'SPECIFIC_ATTRIBUTES'|'COUNT',
ScanFilter={
'string': {
'AttributeValueList': [
{
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
],
'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH'
}
},
ConditionalOperator='AND'|'OR',
ExclusiveStartKey={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
TotalSegments=123,
Segment=123,
ProjectionExpression='string',
FilterExpression='string',
ExpressionAttributeNames={
'string': 'string'
},
ExpressionAttributeValues={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
)
string
[REQUIRED]
The name of the table containing the requested items.
list
Warning
There is a newer parameter available. Use ProjectionExpression instead. Note that if you use AttributesToGet and ProjectionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter allows you to retrieve lists or maps; however, it cannot retrieve individual list or map elements.
The names of one or more attributes to retrieve. If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
Note that AttributesToGet has no effect on provisioned throughput consumption. DynamoDB determines capacity units consumed based on item size, not on the amount of data that is returned to an application.
(string) --
integer
The maximum number of items to evaluate (not necessarily the number of matching items). If DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, and a key in LastEvaluatedKey to apply in a subsequent operation, so that you can pick up where you left off. Also, if the processed data set size exceeds 1 MB before DynamoDB reaches this limit, it stops the operation and returns the matching values up to the limit, and a key in LastEvaluatedKey to apply in a subsequent operation to continue the operation. For more information, see Query and Scan in the Amazon DynamoDB Developer Guide .
string
The attributes to be returned in the result. You can retrieve all item attributes, specific item attributes, or the count of matching items.
ALL_ATTRIBUTES - Returns all of the item attributes.
COUNT - Returns the number of matching items, rather than the matching items themselves.
SPECIFIC_ATTRIBUTES - Returns only the attributes listed in AttributesToGet . This return value is equivalent to specifying AttributesToGet without specifying any value for Select .
If neither Select nor AttributesToGet are specified, DynamoDB defaults to ALL_ATTRIBUTES . You cannot use both AttributesToGet and Select together in a single request, unless the value for Select is SPECIFIC_ATTRIBUTES . (This usage is equivalent to specifying AttributesToGet without any value for Select .)
dict
Warning
There is a newer parameter available. Use FilterExpression instead. Note that if you use ScanFilter and FilterExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A condition that evaluates the scan results and returns only the desired values.
If you specify more than one condition in the ScanFilter map, then by default all of the conditions must evaluate to true. In other words, the conditions are ANDed together. (You can use the ConditionalOperator parameter to OR the conditions instead. If you do this, then at least one of the conditions must evaluate to true, rather than all of them.)
Each ScanFilter element consists of an attribute name to compare, along with the following:
AttributeValueList - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the operator specified in ComparisonOperator . For type Number, value comparisons are numeric. String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters. For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions. For information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
ComparisonOperator - A comparator for evaluating attributes. For example, equals, greater than, less than, etc. The following comparison operators are available: EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN For complete descriptions of all comparison operators, see Condition.
(string) --
(dict) --
Represents the selection criteria for a Query or Scan operation:
For a Query operation, Condition is used for specifying the KeyConditions to use when querying a table or an index. For KeyConditions , only the following comparison operators are supported: EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN Condition is also used in a QueryFilter , which evaluates the query results and returns only the desired values.
For a Scan operation, Condition is used in a ScanFilter , which evaluates the scan results and returns only the desired values.
AttributeValueList (list) --
One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used.
For type Number, value comparisons are numeric.
String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters.
For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ComparisonOperator (string) -- [REQUIRED]
A comparator for evaluating attributes. For example, equals, greater than, less than, etc.
The following comparison operators are available:
EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN
The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
string
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use ConditionalOperator and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A logical operator to apply to the conditions in the ScanFilter map:
AND - If all of the conditions evaluate to true, then the entire map evaluates to true.
OR - If at least one of the conditions evaluate to true, then the entire map evaluates to true.
If you omit ConditionalOperator , then AND is the default.
The operation will succeed only if the entire map evaluates to true.
dict
The primary key of the first item that this operation will evaluate. Use the value that was returned for LastEvaluatedKey in the previous operation.
The data type for ExclusiveStartKey must be String, Number or Binary. No set data types are allowed.
In a parallel scan, a Scan request that includes ExclusiveStartKey must specify the same segment whose previous Scan returned the corresponding value of LastEvaluatedKey .
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
integer
For a parallel Scan request, TotalSegments represents the total number of segments into which the Scan operation will be divided. The value of TotalSegments corresponds to the number of application workers that will perform the parallel scan. For example, if you want to scan a table using four application threads, specify a TotalSegments value of 4.
The value for TotalSegments must be greater than or equal to 1, and less than or equal to 1000000. If you specify a TotalSegments value of 1, the Scan operation will be sequential rather than parallel.
If you specify TotalSegments , you must also specify Segment .
integer
For a parallel Scan request, Segment identifies an individual segment to be scanned by an application worker.
Segment IDs are zero-based, so the first segment is always 0. For example, if you want to scan a table using four application threads, the first thread specifies a Segment value of 0, the second thread specifies 1, and so on.
The value of LastEvaluatedKey returned from a parallel Scan request must be used as ExclusiveStartKey with the same segment ID in a subsequent Scan operation.
The value for Segment must be greater than or equal to 0, and less than the value provided for TotalSegments .
If you specify Segment , you must also specify TotalSegments .
string
One or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.
If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
string
A condition that evaluates the scan results and returns only the desired values.
The condition you specify is applied to the items scanned; any items that do not match the expression are not returned.
dict
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : character in an expression to dereference an attribute value. For example, consider the following expression:
ProductStatus IN ("Available","Backordered","Discontinued")
Now suppose that you specified the following for ExpressionAttributeValues :
{ "a":{"S":"Available"}, "b":{"S":"Backordered"}, "d":{"S":"Discontinued"} }
The expression can now be simplified as follows:
ProductStatus IN (:a,:b,:c)
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Response Syntax
{
'Items': [
{
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
],
'Count': 123,
'ScannedCount': 123,
'LastEvaluatedKey': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
}
}
Response Structure
(dict) --
Represents the output of a Scan operation.
Items (list) --
An array of item attributes that match the scan criteria. Each element in this array consists of an attribute name and the value for that attribute.
(dict) --
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
Count (integer) --
The number of items in the response.
If you set ScanFilter in the request, then Count is the number of items returned after the filter was applied, and ScannedCount is the number of matching items before the filter was applied.
If you did not use a filter in the request, then Count is the same as ScannedCount .
ScannedCount (integer) --
The number of items evaluated, before any ScanFilter is applied. A high ScannedCount value with few, or no, Count results indicates an inefficient Scan operation. For more information, see Count and ScannedCount in the Amazon DynamoDB Developer Guide .
If you did not use a filter in the request, then ScannedCount is the same as Count .
LastEvaluatedKey (dict) --
The primary key of the item where the operation stopped, inclusive of the previous result set. Use this value to start a new operation, excluding this value in the new request.
If LastEvaluatedKey is empty, then the "last page" of results has been processed and there is no more data to be retrieved.
If LastEvaluatedKey is not empty, it does not necessarily mean that there is more data in the result set. The only way to know when you have reached the end of the result set is when LastEvaluatedKey is empty.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ConsumedCapacity (dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
The BatchGetItem operation returns the attributes of one or more items from one or more tables. You identify requested items by primary key.
A single operation can retrieve up to 16 MB of data, which can contain as many as 100 items. BatchGetItem will return a partial result if the response size limit is exceeded, the table's provisioned throughput is exceeded, or an internal processing failure occurs. If a partial result is returned, the operation returns a value for UnprocessedKeys . You can use this value to retry the operation starting with the next item to get.
For example, if you ask to retrieve 100 items, but each individual item is 300 KB in size, the system returns 52 items (so as not to exceed the 16 MB limit). It also returns an appropriate UnprocessedKeys value so you can get the next page of results. If desired, your application can include its own logic to assemble the pages of results into one data set.
If none of the items can be processed due to insufficient provisioned throughput on all of the tables in the request, then BatchGetItem will return a ProvisionedThroughputExceededException . If at least one of the items is successfully processed, then BatchGetItem completes successfully, while returning the keys of the unread items in UnprocessedKeys .
Warning
If DynamoDB returns any unprocessed items, you should retry the batch operation on those items. However, we strongly recommend that you use an exponential backoff algorithm . If you retry the batch operation immediately, the underlying read or write requests can still fail due to throttling on the individual tables. If you delay the batch operation using exponential backoff, the individual requests in the batch are much more likely to succeed.
For more information, go to Batch Operations and Error Handling in the Amazon DynamoDB Developer Guide .
By default, BatchGetItem performs eventually consistent reads on every table in the request. If you want strongly consistent reads instead, you can set ConsistentRead to true for any or all tables.
In order to minimize response latency, BatchGetItem retrieves items in parallel.
When designing your application, keep in mind that DynamoDB does not return attributes in any particular order. To help parse the response by item, include the primary key values for the items in your request in the AttributesToGet parameter.
If a requested item does not exist, it is not returned in the result. Requests for nonexistent items consume the minimum read capacity units according to the type of read. For more information, see Capacity Units Calculations in the Amazon DynamoDB Developer Guide .
Request Syntax
client.batch_get_item(
RequestItems={
'string': {
'Keys': [
{
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
],
'AttributesToGet': [
'string',
],
'ConsistentRead': True|False,
'ProjectionExpression': 'string',
'ExpressionAttributeNames': {
'string': 'string'
}
}
},
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE'
)
dict
[REQUIRED]
A map of one or more table names and, for each table, the corresponding primary keys for the items to retrieve. Each table name can be invoked only once.
Each element in the map consists of the following:
Keys - An array of primary key attribute values that define specific items in the table. For each primary key, you must provide all of the key attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
AttributesToGet - One or more attributes to be retrieved from the table. By default, all attributes are returned. If a specified attribute is not found, it does not appear in the result. Note that AttributesToGet has no effect on provisioned throughput consumption. DynamoDB determines capacity units consumed based on item size, not on the amount of data that is returned to an application.
ConsistentRead - If true , a strongly consistent read is used; if false (the default), an eventually consistent read is used.
(string) --
(dict) --
Represents a set of primary keys and, for each key, the attributes to retrieve from the table.
For each primary key, you must provide all of the key attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
Keys (list) -- [REQUIRED]
The primary key attribute values that define the items and the attributes associated with the items.
(dict) --
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
AttributesToGet (list) --
One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
(string) --
ConsistentRead (boolean) --
The consistency of a read operation. If set to true , then a strongly consistent read is used; otherwise, an eventually consistent read is used.
ProjectionExpression (string) --
One or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.
If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
ExpressionAttributeNames (dict) --
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
dict
Response Syntax
{
'Responses': {
'string': [
{
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
]
},
'UnprocessedKeys': {
'string': {
'Keys': [
{
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
],
'AttributesToGet': [
'string',
],
'ConsistentRead': True|False,
'ProjectionExpression': 'string',
'ExpressionAttributeNames': {
'string': 'string'
}
}
},
'ConsumedCapacity': [
{
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
},
]
}
Response Structure
(dict) --
Represents the output of a BatchGetItem operation.
Responses (dict) --
A map of table name to a list of items. Each object in Responses consists of a table name, along with a map of attribute data consisting of the data type and attribute value.
(string) --
(list) --
(dict) --
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
UnprocessedKeys (dict) --
A map of tables and their respective keys that were not processed with the current response. The UnprocessedKeys value is in the same form as RequestItems , so the value can be provided directly to a subsequent BatchGetItem operation. For more information, see RequestItems in the Request Parameters section.
Each element consists of:
Keys - An array of primary key attribute values that define specific items in the table.
AttributesToGet - One or more attributes to be retrieved from the table or index. By default, all attributes are returned. If a specified attribute is not found, it does not appear in the result.
ConsistentRead - The consistency of a read operation. If set to true , then a strongly consistent read is used; otherwise, an eventually consistent read is used.
If there are no unprocessed keys remaining, the response contains an empty UnprocessedKeys map.
(string) --
(dict) --
Represents a set of primary keys and, for each key, the attributes to retrieve from the table.
For each primary key, you must provide all of the key attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
Keys (list) --
The primary key attribute values that define the items and the attributes associated with the items.
(dict) --
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
AttributesToGet (list) --
One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
(string) --
ConsistentRead (boolean) --
The consistency of a read operation. If set to true , then a strongly consistent read is used; otherwise, an eventually consistent read is used.
ProjectionExpression (string) --
One or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.
If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
ExpressionAttributeNames (dict) --
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
ConsumedCapacity (list) --
The write capacity units consumed by the operation.
Each element consists of:
TableName - The table that consumed the provisioned throughput.
CapacityUnits - The total number of capacity units consumed.
(dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
Updates the provisioned throughput for the given table. Setting the throughput for a table helps you manage performance and is part of the provisioned throughput feature of DynamoDB.
The provisioned throughput values can be upgraded or downgraded based on the maximums and minimums listed in the Limits section in the Amazon DynamoDB Developer Guide .
The table must be in the ACTIVE state for this operation to succeed. UpdateTable is an asynchronous operation; while executing the operation, the table is in the UPDATING state. While the table is in the UPDATING state, the table still has the provisioned throughput from before the call. The new provisioned throughput setting is in effect only when the table returns to the ACTIVE state after the UpdateTable operation.
You cannot add, modify or delete indexes using UpdateTable . Indexes can only be defined at table creation time.
Request Syntax
client.update_table(
TableName='string',
ProvisionedThroughput={
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
GlobalSecondaryIndexUpdates=[
{
'Update': {
'IndexName': 'string',
'ProvisionedThroughput': {
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
}
}
},
]
)
string
[REQUIRED]
The name of the table to be updated.
dict
Represents the provisioned throughput settings for a specified table or index. The settings can be modified using the UpdateTable operation.
For current minimum and maximum provisioned throughput values, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) -- [REQUIRED]
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
WriteCapacityUnits (integer) -- [REQUIRED]
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
list
An array of one or more global secondary indexes on the table, together with provisioned throughput settings for each index.
(dict) --
Represents the new provisioned throughput settings to apply to a global secondary index.
Update (dict) --
The name of a global secondary index, along with the updated provisioned throughput settings that are to be applied to that index.
IndexName (string) -- [REQUIRED]
The name of the global secondary index to be updated.
ProvisionedThroughput (dict) -- [REQUIRED]
Represents the provisioned throughput settings for a specified table or index. The settings can be modified using the UpdateTable operation.
For current minimum and maximum provisioned throughput values, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) -- [REQUIRED]
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
WriteCapacityUnits (integer) -- [REQUIRED]
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
dict
Response Syntax
{
'TableDescription': {
'AttributeDefinitions': [
{
'AttributeName': 'string',
'AttributeType': 'S'|'N'|'B'
},
],
'TableName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'TableStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'CreationDateTime': datetime(2015, 1, 1),
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'TableSizeBytes': 123,
'ItemCount': 123,
'LocalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
],
'GlobalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
]
}
}
Response Structure
(dict) --
Represents the output of an UpdateTable operation.
TableDescription (dict) --
Represents the properties of a table.
AttributeDefinitions (list) --
An array of AttributeDefinition objects. Each of these objects describes one attribute in the table and index key schema.
Each AttributeDefinition object in this array is composed of:
AttributeName - The name of the attribute.
AttributeType - The data type for the attribute.
(dict) --
Represents an attribute for describing the key schema for the table and indexes.
AttributeName (string) --
A name for the attribute.
AttributeType (string) --
The data type for the attribute.
TableName (string) --
The name of the table.
KeySchema (list) --
The primary key structure for the table. Each KeySchemaElement consists of:
AttributeName - The name of the attribute.
KeyType - The key type for the attribute. Can be either HASH or RANGE .
For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide .
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
TableStatus (string) --
The current state of the table:
CREATING - The table is being created, as the result of a CreateTable operation.
UPDATING - The table is being updated, as the result of an UpdateTable operation.
DELETING - The table is being deleted, as the result of a DeleteTable operation.
ACTIVE - The table is ready for use.
CreationDateTime (datetime) --
The date and time when the table was created, in UNIX epoch time format.
ProvisionedThroughput (dict) --
The provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
TableSizeBytes (integer) --
The total size of the specified table, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified table. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
LocalSecondaryIndexes (list) --
Represents one or more local secondary indexes on the table. Each index is scoped to a given hash key value. Tables with one or more local secondary indexes are subject to an item collection size limit, where the amount of data within a given item collection cannot exceed 10 GB. Each element is composed of:
IndexName - The name of the local secondary index.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
IndexSizeBytes - Represents the total size of the index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount - Represents the number of items in the index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a local secondary index.
IndexName (string) --
Represents the name of the local secondary index.
KeySchema (list) --
The complete index key schema, which consists of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
GlobalSecondaryIndexes (list) --
The global secondary indexes, if any, on the table. Each index is scoped to a given hash key value. Each element is composed of:
IndexName - The name of the global secondary index.
IndexSizeBytes - The total size of the global secondary index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
IndexStatus - The current status of the global secondary index:
CREATING - The index is being created.
UPDATING - The index is being updated.
DELETING - The index is being deleted.
ACTIVE - The index is ready for use.
ItemCount - The number of items in the global secondary index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
ProvisionedThroughput - The provisioned throughput settings for the global secondary index, consisting of read and write capacity units, along with data about increases and decreases.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a global secondary index.
IndexName (string) --
The name of the global secondary index.
KeySchema (list) --
The complete key schema for the global secondary index, consisting of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexStatus (string) --
The current state of the global secondary index:
CREATING - The index is being created, as the result of a CreateTable or UpdateTable operation.
UPDATING - The index is being updated, as the result of a CreateTable or UpdateTable operation.
DELETING - The index is being deleted, as the result of a DeleteTable operation.
ACTIVE - The index is ready for use.
ProvisionedThroughput (dict) --
Represents the provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
The CreateTable operation adds a new table to your account. In an AWS account, table names must be unique within each region. That is, you can have two tables with same name if you create the tables in different regions.
CreateTable is an asynchronous operation. Upon receiving a CreateTable request, DynamoDB immediately returns a response with a TableStatus of CREATING . After the table is created, DynamoDB sets the TableStatus to ACTIVE . You can perform read and write operations only on an ACTIVE table.
If you want to create multiple tables with secondary indexes on them, you must create them sequentially. Only one table with secondary indexes can be in the CREATING state at any given time.
You can use the DescribeTable API to check the table status.
Request Syntax
client.create_table(
AttributeDefinitions=[
{
'AttributeName': 'string',
'AttributeType': 'S'|'N'|'B'
},
],
TableName='string',
KeySchema=[
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
LocalSecondaryIndexes=[
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
}
},
],
GlobalSecondaryIndexes=[
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'ProvisionedThroughput': {
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
}
},
],
ProvisionedThroughput={
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
}
)
list
[REQUIRED]
An array of attributes that describe the key schema for the table and indexes.
(dict) --
Represents an attribute for describing the key schema for the table and indexes.
AttributeName (string) -- [REQUIRED]
A name for the attribute.
AttributeType (string) -- [REQUIRED]
The data type for the attribute.
string
[REQUIRED]
The name of the table to create.
list
[REQUIRED]
Specifies the attributes that make up the primary key for a table or an index. The attributes in KeySchema must also be defined in the AttributeDefinitions array. For more information, see Data Model in the Amazon DynamoDB Developer Guide .
Each KeySchemaElement in the array is composed of:
AttributeName - The name of this key attribute.
KeyType - Determines whether the key attribute is HASH or RANGE .
For a primary key that consists of a hash attribute, you must specify exactly one element with a KeyType of HASH .
For a primary key that consists of hash and range attributes, you must specify exactly two elements, in this order: The first element must have a KeyType of HASH , and the second element must have a KeyType of RANGE .
For more information, see Specifying the Primary Key in the Amazon DynamoDB Developer Guide .
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) -- [REQUIRED]
The name of a key attribute.
KeyType (string) -- [REQUIRED]
The attribute data, consisting of the data type and the attribute value itself.
list
One or more local secondary indexes (the maximum is five) to be created on the table. Each index is scoped to a given hash key value. There is a 10 GB size limit per hash key; otherwise, the size of a local secondary index is unconstrained.
Each local secondary index in the array includes the following:
IndexName - The name of the local secondary index. Must be unique only for this table.
KeySchema - Specifies the key schema for the local secondary index. The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(dict) --
Represents a local secondary index.
IndexName (string) -- [REQUIRED]
The name of the local secondary index. The name must be unique among all other indexes on this table.
KeySchema (list) -- [REQUIRED]
The complete key schema for the local secondary index, consisting of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) -- [REQUIRED]
The name of a key attribute.
KeyType (string) -- [REQUIRED]
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) -- [REQUIRED]
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
list
One or more global secondary indexes (the maximum is five) to be created on the table. Each global secondary index in the array includes the following:
IndexName - The name of the global secondary index. Must be unique only for this table.
KeySchema - Specifies the key schema for the global secondary index.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
ProvisionedThroughput - The provisioned throughput settings for the global secondary index, consisting of read and write capacity units.
(dict) --
Represents a global secondary index.
IndexName (string) -- [REQUIRED]
The name of the global secondary index. The name must be unique among all other indexes on this table.
KeySchema (list) -- [REQUIRED]
The complete key schema for a global secondary index, which consists of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) -- [REQUIRED]
The name of a key attribute.
KeyType (string) -- [REQUIRED]
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) -- [REQUIRED]
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
ProvisionedThroughput (dict) -- [REQUIRED]
Represents the provisioned throughput settings for a specified table or index. The settings can be modified using the UpdateTable operation.
For current minimum and maximum provisioned throughput values, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) -- [REQUIRED]
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
WriteCapacityUnits (integer) -- [REQUIRED]
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
dict
[REQUIRED]
Represents the provisioned throughput settings for a specified table or index. The settings can be modified using the UpdateTable operation.
For current minimum and maximum provisioned throughput values, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) -- [REQUIRED]
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
WriteCapacityUnits (integer) -- [REQUIRED]
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException . For more information, see Specifying Read and Write Requirements in the Amazon DynamoDB Developer Guide .
dict
Response Syntax
{
'TableDescription': {
'AttributeDefinitions': [
{
'AttributeName': 'string',
'AttributeType': 'S'|'N'|'B'
},
],
'TableName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'TableStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'CreationDateTime': datetime(2015, 1, 1),
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'TableSizeBytes': 123,
'ItemCount': 123,
'LocalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
],
'GlobalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
]
}
}
Response Structure
(dict) --
Represents the output of a CreateTable operation.
TableDescription (dict) --
Represents the properties of a table.
AttributeDefinitions (list) --
An array of AttributeDefinition objects. Each of these objects describes one attribute in the table and index key schema.
Each AttributeDefinition object in this array is composed of:
AttributeName - The name of the attribute.
AttributeType - The data type for the attribute.
(dict) --
Represents an attribute for describing the key schema for the table and indexes.
AttributeName (string) --
A name for the attribute.
AttributeType (string) --
The data type for the attribute.
TableName (string) --
The name of the table.
KeySchema (list) --
The primary key structure for the table. Each KeySchemaElement consists of:
AttributeName - The name of the attribute.
KeyType - The key type for the attribute. Can be either HASH or RANGE .
For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide .
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
TableStatus (string) --
The current state of the table:
CREATING - The table is being created, as the result of a CreateTable operation.
UPDATING - The table is being updated, as the result of an UpdateTable operation.
DELETING - The table is being deleted, as the result of a DeleteTable operation.
ACTIVE - The table is ready for use.
CreationDateTime (datetime) --
The date and time when the table was created, in UNIX epoch time format.
ProvisionedThroughput (dict) --
The provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
TableSizeBytes (integer) --
The total size of the specified table, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified table. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
LocalSecondaryIndexes (list) --
Represents one or more local secondary indexes on the table. Each index is scoped to a given hash key value. Tables with one or more local secondary indexes are subject to an item collection size limit, where the amount of data within a given item collection cannot exceed 10 GB. Each element is composed of:
IndexName - The name of the local secondary index.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
IndexSizeBytes - Represents the total size of the index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount - Represents the number of items in the index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a local secondary index.
IndexName (string) --
Represents the name of the local secondary index.
KeySchema (list) --
The complete index key schema, which consists of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
GlobalSecondaryIndexes (list) --
The global secondary indexes, if any, on the table. Each index is scoped to a given hash key value. Each element is composed of:
IndexName - The name of the global secondary index.
IndexSizeBytes - The total size of the global secondary index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
IndexStatus - The current status of the global secondary index:
CREATING - The index is being created.
UPDATING - The index is being updated.
DELETING - The index is being deleted.
ACTIVE - The index is ready for use.
ItemCount - The number of items in the global secondary index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
ProvisionedThroughput - The provisioned throughput settings for the global secondary index, consisting of read and write capacity units, along with data about increases and decreases.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a global secondary index.
IndexName (string) --
The name of the global secondary index.
KeySchema (list) --
The complete key schema for the global secondary index, consisting of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexStatus (string) --
The current state of the global secondary index:
CREATING - The index is being created, as the result of a CreateTable or UpdateTable operation.
UPDATING - The index is being updated, as the result of a CreateTable or UpdateTable operation.
DELETING - The index is being deleted, as the result of a DeleteTable operation.
ACTIVE - The index is ready for use.
ProvisionedThroughput (dict) --
Represents the provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
The BatchWriteItem operation puts or deletes multiple items in one or more tables. A single call to BatchWriteItem can write up to 16 MB of data, which can comprise as many as 25 put or delete requests. Individual items to be written can be as large as 400 KB.
The individual PutItem and DeleteItem operations specified in BatchWriteItem are atomic; however BatchWriteItem as a whole is not. If any requested operations fail because the table's provisioned throughput is exceeded or an internal processing failure occurs, the failed operations are returned in the UnprocessedItems response parameter. You can investigate and optionally resend the requests. Typically, you would call BatchWriteItem in a loop. Each iteration would check for unprocessed items and submit a new BatchWriteItem request with those unprocessed items until all items have been processed.
Note that if none of the items can be processed due to insufficient provisioned throughput on all of the tables in the request, then BatchWriteItem will return a ProvisionedThroughputExceededException .
Warning
If DynamoDB returns any unprocessed items, you should retry the batch operation on those items. However, we strongly recommend that you use an exponential backoff algorithm . If you retry the batch operation immediately, the underlying read or write requests can still fail due to throttling on the individual tables. If you delay the batch operation using exponential backoff, the individual requests in the batch are much more likely to succeed.
For more information, go to Batch Operations and Error Handling in the Amazon DynamoDB Developer Guide .
With BatchWriteItem , you can efficiently write or delete large amounts of data, such as from Amazon Elastic MapReduce (EMR), or copy data from another database into DynamoDB. In order to improve performance with these large-scale operations, BatchWriteItem does not behave in the same way as individual PutItem and DeleteItem calls would For example, you cannot specify conditions on individual put and delete requests, and BatchWriteItem does not return deleted items in the response.
If you use a programming language that supports concurrency, such as Java, you can use threads to write items in parallel. Your application must include the necessary logic to manage the threads. With languages that don't support threading, such as PHP, you must update or delete the specified items one at a time. In both situations, BatchWriteItem provides an alternative where the API performs the specified put and delete operations in parallel, giving you the power of the thread pool approach without having to introduce complexity into your application.
Parallel processing reduces latency, but each specified put and delete request consumes the same number of write capacity units whether it is processed in parallel or not. Delete operations on nonexistent items consume one write capacity unit.
If one or more of the following is true, DynamoDB rejects the entire batch write operation:
One or more tables specified in the BatchWriteItem request does not exist.
Primary key attributes specified on an item in the request do not match those in the corresponding table's primary key schema.
You try to perform multiple operations on the same item in the same BatchWriteItem request. For example, you cannot put and delete the same item in the same BatchWriteItem request.
There are more than 25 requests in the batch.
Any individual item in a batch exceeds 400 KB.
The total request size exceeds 16 MB.
Request Syntax
client.batch_write_item(
RequestItems={
'string': [
{
'PutRequest': {
'Item': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
},
'DeleteRequest': {
'Key': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
}
},
]
},
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
ReturnItemCollectionMetrics='SIZE'|'NONE'
)
dict
[REQUIRED]
A map of one or more table names and, for each table, a list of operations to be performed (DeleteRequest or PutRequest ). Each element in the map consists of the following:
DeleteRequest - Perform a DeleteItem operation on the specified item. The item to be deleted is identified by a Key subelement:
Key - A map of primary key attribute values that uniquely identify the ! item. Each entry in this map consists of an attribute name and an attribute value. For each primary key, you must provide all of the key attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
PutRequest - Perform a PutItem operation on the specified item. The item to be put is identified by an Item subelement:
Item - A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values will be rejected with a ValidationException exception. If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
(string) --
(list) --
(dict) --
Represents an operation to perform - either DeleteItem or PutItem . You can only specify one of these operations, not both, in a single WriteRequest . If you do need to perform both of these operations, you will need to specify two separate WriteRequest objects.
PutRequest (dict) --
A request to perform a PutItem operation.
Item (dict) -- [REQUIRED]
A map of attribute name to attribute values, representing the primary key of an item to be processed by PutItem . All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema. If any attributes are present in the item which are part of an index key schema for the table, their types must match the index key schema.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
DeleteRequest (dict) --
A request to perform a DeleteItem operation.
Key (dict) -- [REQUIRED]
A map of attribute name to attribute values, representing the primary key of the item to delete. All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
string
A value that if set to SIZE , the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.
dict
Response Syntax
{
'UnprocessedItems': {
'string': [
{
'PutRequest': {
'Item': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
},
'DeleteRequest': {
'Key': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
}
},
]
},
'ItemCollectionMetrics': {
'string': [
{
'ItemCollectionKey': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'SizeEstimateRangeGB': [
123.0,
]
},
]
},
'ConsumedCapacity': [
{
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
},
]
}
Response Structure
(dict) --
Represents the output of a BatchWriteItem operation.
UnprocessedItems (dict) --
A map of tables and requests against those tables that were not processed. The UnprocessedItems value is in the same form as RequestItems , so you can provide this value directly to a subsequent BatchGetItem operation. For more information, see RequestItems in the Request Parameters section.
Each UnprocessedItems entry consists of a table name and, for that table, a list of operations to perform (DeleteRequest or PutRequest ).
DeleteRequest - Perform a DeleteItem operation on the specified item. The item to be deleted is identified by a Key subelement:
Key - A map of primary key attribute values that uniquely identify the item. Each entry in this map consists of an attribute name and an attribute value.
PutRequest - Perform a PutItem operation on the specified item. The item to be put is identified by an Item subelement:
Item - A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values will be rejected with a ValidationException exception. If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
If there are no unprocessed items remaining, the response contains an empty UnprocessedItems map.
(string) --
(list) --
(dict) --
Represents an operation to perform - either DeleteItem or PutItem . You can only specify one of these operations, not both, in a single WriteRequest . If you do need to perform both of these operations, you will need to specify two separate WriteRequest objects.
PutRequest (dict) --
A request to perform a PutItem operation.
Item (dict) --
A map of attribute name to attribute values, representing the primary key of an item to be processed by PutItem . All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema. If any attributes are present in the item which are part of an index key schema for the table, their types must match the index key schema.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
DeleteRequest (dict) --
A request to perform a DeleteItem operation.
Key (dict) --
A map of attribute name to attribute values, representing the primary key of the item to delete. All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ItemCollectionMetrics (dict) --
A list of tables that were processed by BatchWriteItem and, for each table, information about any item collections that were affected by individual DeleteItem or PutItem operations.
Each entry consists of the following subelements:
ItemCollectionKey - The hash key value of the item collection. This is the same as the hash key of the item.
SizeEstimateRange - An estimate of item collection size, expressed in GB. This is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on the table. Use this estimate to measure whether a local secondary index is approaching its size limit. The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
(string) --
(list) --
(dict) --
Information about item collections, if any, that were affected by the operation. ItemCollectionMetrics is only returned if the request asked for it. If the table does not have any local secondary indexes, this information is not returned in the response.
ItemCollectionKey (dict) --
The hash key value of the item collection. This value is the same as the hash key of the item.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
SizeEstimateRangeGB (list) --
An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit.
The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
(float) --
ConsumedCapacity (list) --
The capacity units consumed by the operation.
Each element consists of:
TableName - The table that consumed the provisioned throughput.
CapacityUnits - The total number of capacity units consumed.
(dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
Edits an existing item's attributes, or adds a new item to the table if it does not already exist. You can put, delete, or add attribute values. You can also perform a conditional update (insert a new attribute name-value pair if it doesn't exist, or replace an existing name-value pair if it has certain expected attribute values).
You can also return the item's attribute values in the same UpdateItem operation using the ReturnValues parameter.
Request Syntax
client.update_item(
TableName='string',
Key={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
AttributeUpdates={
'string': {
'Value': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
'Action': 'ADD'|'PUT'|'DELETE'
}
},
Expected={
'string': {
'Value': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
'Exists': True|False,
'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH',
'AttributeValueList': [
{
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
]
}
},
ConditionalOperator='AND'|'OR',
ReturnValues='NONE'|'ALL_OLD'|'UPDATED_OLD'|'ALL_NEW'|'UPDATED_NEW',
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
ReturnItemCollectionMetrics='SIZE'|'NONE',
UpdateExpression='string',
ConditionExpression='string',
ExpressionAttributeNames={
'string': 'string'
},
ExpressionAttributeValues={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
)
string
[REQUIRED]
The name of the table containing the item to update.
dict
[REQUIRED]
The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.
For the primary key, you must provide all of the attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Warning
There is a newer parameter available. Use UpdateExpression instead. Note that if you use AttributeUpdates and UpdateExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter can be used for modifying top-level attributes; however, it does not support individual list or map elements.
The names of attributes to be modified, the action to perform on each, and the new value for each. If you are updating an attribute that is an index key attribute for any indexes on that table, the attribute type must match the index key type defined in the AttributesDefinition of the table description. You can use UpdateItem to update any nonkey attributes.
Attribute values cannot be null. String and Binary type attributes must have lengths greater than zero. Set type attributes must not be empty. Requests with empty values will be rejected with a ValidationException exception.
Each AttributeUpdates element consists of an attribute name to modify, along with the following:
Value - The new value, if applicable, for this attribute.
Action - A value that specifies how to perform the update. This action is only valid for an existing attribute whose data type is Number or is a set; do not use ADD for other data types. If an item with the specified primary key is found in the table, the following values perform the following actions:
PUT - Adds the specified attribute to the item. If the attribute already exists, it is replaced by the new value.
DELETE - Removes the attribute and its value, if no value is specified for DELETE . The data type of the specified value must match the existing value's data type. If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set [a,b,c] and the DELETE action specifies [a,c] , then the final attribute value is [b] . Specifying an empty set is an error.
ADD - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of ADD depends on the data type of the attribute:
If the existing attribute is a number, and if Value is also a number, then Value is mathematically added to the existing attribute. If Value is a negative number, then it is subtracted from the existing attribute.
If the existing data type is a set, and if Value is also a set, then Value is appended to the existing set. For example, if the attribute value is the set [1,2] , and the ADD action specified [3] , then the final attribute value is [1,2,3] . An error occurs if an ADD action is specified for a set attribute and the attribute type specified does not match the existing set type. Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, Value must also be a set of strings.
If no item with the specified key is found in the table, the following values perform the following actions:
PUT - Causes DynamoDB to create a new item with the specified primary key, and then adds the attribute.
DELETE - Causes nothing to happen; there is no attribute to delete.
ADD - Causes DynamoDB to creat an item with the supplied primary key and number (or set of numbers) for the attribute value. The only data types allowed are Number and Number Set.
If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
(string) --
(dict) --
For the UpdateItem operation, represents the attributes to be modified, the action to perform on each, and the new value for each.
Attribute values cannot be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests with empty values will be rejected with a ValidationException exception.
Value (dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
Action (string) --
Specifies how to perform the update. Valid values are PUT (default), DELETE , and ADD . The behavior depends on whether the specified primary key already exists in the table.
If an item with the specified Key is found in the table:
PUT - Adds the specified attribute to the item. If the attribute already exists, it is replaced by the new value.
DELETE - If no value is specified, the attribute and its value are removed from the item. The data type of the specified value must match the existing value's data type. If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set [a,b,c] and the DELETE action specified [a,c] , then the final attribute value would be [b] . Specifying an empty set is an error.
ADD - If the attribute does not already exist, then the attribute and its values are added to the item. If the attribute does exist, then the behavior of ADD depends on the data type of the attribute:
If the existing attribute is a number, and if Value is also a number, then the Value is mathematically added to the existing attribute. If Value is a negative number, then it is subtracted from the existing attribute.
If the existing data type is a set, and if the Value is also a set, then the Value is added to the existing set. (This is a set operation, not mathematical addition.) For example, if the attribute value was the set [1,2] , and the ADD action specified [3] , then the final attribute value would be [1,2,3] . An error occurs if an Add action is specified for a set attribute and the attribute type specified does not match the existing set type. Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the Value must also be a set of strings. The same holds true for number sets and binary sets.
This action is only valid for an existing attribute whose data type is number or is a set. Do not use ADD for any other data types.
If no item with the specified Key is found:
PUT - DynamoDB creates a new item with the specified primary key, and then adds the attribute.
DELETE - Nothing happens; there is no attribute to delete.
ADD - DynamoDB creates an item with the supplied primary key and number (or set of numbers) for the attribute value. The only data types allowed are number and number set; no other data types can be specified.
dict
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use Expected and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A map of attribute/condition pairs. Expected provides a conditional block for the UpdateItem operation.
Each element of Expected consists of an attribute name, a comparison operator, and one or more values. DynamoDB compares the attribute with the value(s) you supplied, using the comparison operator. For each Expected element, the result of the evaluation is either true or false.
If you specify more than one element in the Expected map, then by default all of the conditions must evaluate to true. In other words, the conditions are ANDed together. (You can use the ConditionalOperator parameter to OR the conditions instead. If you do this, then at least one of the conditions must evaluate to true, rather than all of them.)
If the Expected map evaluates to true, then the conditional operation succeeds; otherwise, it fails.
Expected contains the following:
AttributeValueList - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used. For type Number, value comparisons are numeric. String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters. For type Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
ComparisonOperator - A comparator for evaluating attributes in the AttributeValueList . When performing the comparison, DynamoDB uses strongly consistent reads. The following comparison operators are available: EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
For backward compatibility with previous DynamoDB releases, the following parameters can be used instead of AttributeValueList and ComparisonOperator :
Value - A value for DynamoDB to compare with an attribute.
Exists - A Boolean value that causes DynamoDB to evaluate the value before attempting the conditional operation:
If Exists is true , DynamoDB will check to see if that attribute value already exists in the table. If it is found, then the condition evaluates to true; otherwise the condition evaluate to false.
If Exists is false , DynamoDB assumes that the attribute value does not exist in the table. If in fact the value does not exist, then the assumption is valid and the condition evaluates to true. If the value is found, despite the assumption that it does not exist, the condition evaluates to false.
The Value and Exists parameters are incompatible with AttributeValueList and ComparisonOperator . Note that if you use both sets of parameters at once, DynamoDB will return a ValidationException exception.
(string) --
(dict) --
Represents a condition to be compared with an attribute value. This condition can be used with DeleteItem , PutItem or UpdateItem operations; if the comparison evaluates to true, the operation succeeds; if not, the operation fails. You can use ExpectedAttributeValue in one of two different ways:
Use AttributeValueList to specify one or more values to compare against an attribute. Use ComparisonOperator to specify how you want to perform the comparison. If the comparison evaluates to true, then the conditional operation succeeds.
>Use Value to specify a value that DynamoDB will compare against an attribute. If the values match, then ExpectedAttributeValue evaluates to true and the conditional operation succeeds. Optionally, you can also set Exists to false, indicating that you do not expect to find the attribute value in the table. In this case, the conditional operation succeeds only if the comparison evaluates to false.
Value and Exists are incompatible with AttributeValueList and ComparisonOperator . Note that if you use both sets of parameters at once, DynamoDB will return a ValidationException exception.
Value (dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
Exists (boolean) --
Causes DynamoDB to evaluate the value before attempting a conditional operation:
If Exists is true , DynamoDB will check to see if that attribute value already exists in the table. If it is found, then the operation succeeds. If it is not found, the operation fails with a ConditionalCheckFailedException .
If Exists is false , DynamoDB assumes that the attribute value does not exist in the table. If in fact the value does not exist, then the assumption is valid and the operation succeeds. If the value is found, despite the assumption that it does not exist, the operation fails with a ConditionalCheckFailedException .
The default setting for Exists is true . If you supply a Value all by itself, DynamoDB assumes the attribute exists: You don't have to set Exists to true , because it is implied.
DynamoDB returns a ValidationException if:
Exists is true but there is no Value to check. (You expect a value to exist, but don't specify what that value is.)
Exists is false but you also specify a Value . (You cannot expect an attribute to have a value, while also expecting it not to exist.)
ComparisonOperator (string) --
A comparator for evaluating attributes in the AttributeValueList . For example, equals, greater than, less than, etc.
The following comparison operators are available:
EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN
The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
AttributeValueList (list) --
One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used.
For type Number, value comparisons are numeric.
String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters.
For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
For information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
string
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use ConditionalOperator and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A logical operator to apply to the conditions in the Expected map:
AND - If all of the conditions evaluate to true, then the entire map evaluates to true.
OR - If at least one of the conditions evaluate to true, then the entire map evaluates to true.
If you omit ConditionalOperator , then AND is the default.
The operation will succeed only if the entire map evaluates to true.
string
Use ReturnValues if you want to get the item attributes as they appeared either before or after they were updated. For UpdateItem , the valid values are:
NONE - If ReturnValues is not specified, or if its value is NONE , then nothing is returned. (This setting is the default for ReturnValues .)
ALL_OLD - If UpdateItem overwrote an attribute name-value pair, then the content of the old item is returned.
UPDATED_OLD - The old versions of only the updated attributes are returned.
ALL_NEW - All of the attributes of the new version of the item are returned.
UPDATED_NEW - The new versions of only the updated attributes are returned.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
string
A value that if set to SIZE , the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.
string
An expression that defines one or more attributes to be updated, the action to be performed on them, and new value(s) for them.
The following action values are available for UpdateExpression .
SET - Adds one or more attributes and values to an item. If any of these attribute already exist, they are replaced by the new values. You can also use SET to add or subtract from an attribute that is of type Number. SET supports the following functions:
if_not_exists (path, operand) - if the item does not contain an attribute at the specified path, then if_not_exists evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.
list_append (operand, operand) - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.
These function names are case-sensitive.
REMOVE - Removes one or more attributes from an item.
ADD - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of ADD depends on the data type of the attribute:
If the existing attribute is a number, and if Value is also a number, then Value is mathematically added to the existing attribute. If Value is a negative number, then it is subtracted from the existing attribute.
If the existing data type is a set and if Value is also a set, then Value is added to the existing set. For example, if the attribute value is the set [1,2] , and the ADD action specified [3] , then the final attribute value is [1,2,3] . An error occurs if an ADD action is specified for a set attribute and the attribute type specified does not match the existing set type. Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the Value must also be a set of strings.
Warning
The ADD action only supports Number and set data types. In addition, ADD can only be used on top-level attributes, not nested attributes.
DELETE - Deletes an element from a set. If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set [a,b,c] and the DELETE action specifies [a,c] , then the final attribute value is [b] . Specifying an empty set is an error.
Warning
The DELETE action only supports Number and set data types. In addition, DELETE can only be used on top-level attributes, not nested attributes.
You can have many actions in a single expression, such as the following: SET a=:value1, b=:value2 DELETE :value3, :value4, :value5
An expression can contain any of the following:
Boolean functions: ATTRIBUTE_EXIST | CONTAINS | BEGINS_WITH
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: NOT | AND | OR
string
A condition that must be satisfied in order for a conditional update to succeed.
An expression can contain any of the following:
Boolean functions: ATTRIBUTE_EXIST | CONTAINS | BEGINS_WITH
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: NOT | AND | OR
dict
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : character in an expression to dereference an attribute value. For example, consider the following expression:
ProductStatus IN ("Available","Backordered","Discontinued")
Now suppose that you specified the following for ExpressionAttributeValues :
{ "a":{"S":"Available"}, "b":{"S":"Backordered"}, "d":{"S":"Discontinued"} }
The expression can now be simplified as follows:
ProductStatus IN (:a,:b,:c)
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Response Syntax
{
'Attributes': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
},
'ItemCollectionMetrics': {
'ItemCollectionKey': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'SizeEstimateRangeGB': [
123.0,
]
}
}
Response Structure
(dict) --
Represents the output of an UpdateItem operation.
Attributes (dict) --
A map of attribute values as they appeared before the UpdateItem operation. This map only appears if ReturnValues was specified as something other than NONE in the request. Each element represents one attribute.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ConsumedCapacity (dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
ItemCollectionMetrics (dict) --
Information about item collections, if any, that were affected by the operation. ItemCollectionMetrics is only returned if the request asked for it. If the table does not have any local secondary indexes, this information is not returned in the response.
ItemCollectionKey (dict) --
The hash key value of the item collection. This value is the same as the hash key of the item.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
SizeEstimateRangeGB (list) --
An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit.
The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
(float) --
Returns information about the table, including the current status of the table, when it was created, the primary key schema, and any indexes on the table.
Request Syntax
client.describe_table(
TableName='string'
)
string
[REQUIRED]
The name of the table to describe.
dict
Response Syntax
{
'Table': {
'AttributeDefinitions': [
{
'AttributeName': 'string',
'AttributeType': 'S'|'N'|'B'
},
],
'TableName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'TableStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'CreationDateTime': datetime(2015, 1, 1),
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'TableSizeBytes': 123,
'ItemCount': 123,
'LocalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
],
'GlobalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
]
}
}
Response Structure
(dict) --
Represents the output of a DescribeTable operation.
Table (dict) --
Represents the properties of a table.
AttributeDefinitions (list) --
An array of AttributeDefinition objects. Each of these objects describes one attribute in the table and index key schema.
Each AttributeDefinition object in this array is composed of:
AttributeName - The name of the attribute.
AttributeType - The data type for the attribute.
(dict) --
Represents an attribute for describing the key schema for the table and indexes.
AttributeName (string) --
A name for the attribute.
AttributeType (string) --
The data type for the attribute.
TableName (string) --
The name of the table.
KeySchema (list) --
The primary key structure for the table. Each KeySchemaElement consists of:
AttributeName - The name of the attribute.
KeyType - The key type for the attribute. Can be either HASH or RANGE .
For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide .
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
TableStatus (string) --
The current state of the table:
CREATING - The table is being created, as the result of a CreateTable operation.
UPDATING - The table is being updated, as the result of an UpdateTable operation.
DELETING - The table is being deleted, as the result of a DeleteTable operation.
ACTIVE - The table is ready for use.
CreationDateTime (datetime) --
The date and time when the table was created, in UNIX epoch time format.
ProvisionedThroughput (dict) --
The provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
TableSizeBytes (integer) --
The total size of the specified table, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified table. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
LocalSecondaryIndexes (list) --
Represents one or more local secondary indexes on the table. Each index is scoped to a given hash key value. Tables with one or more local secondary indexes are subject to an item collection size limit, where the amount of data within a given item collection cannot exceed 10 GB. Each element is composed of:
IndexName - The name of the local secondary index.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
IndexSizeBytes - Represents the total size of the index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount - Represents the number of items in the index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a local secondary index.
IndexName (string) --
Represents the name of the local secondary index.
KeySchema (list) --
The complete index key schema, which consists of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
GlobalSecondaryIndexes (list) --
The global secondary indexes, if any, on the table. Each index is scoped to a given hash key value. Each element is composed of:
IndexName - The name of the global secondary index.
IndexSizeBytes - The total size of the global secondary index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
IndexStatus - The current status of the global secondary index:
CREATING - The index is being created.
UPDATING - The index is being updated.
DELETING - The index is being deleted.
ACTIVE - The index is ready for use.
ItemCount - The number of items in the global secondary index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
ProvisionedThroughput - The provisioned throughput settings for the global secondary index, consisting of read and write capacity units, along with data about increases and decreases.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a global secondary index.
IndexName (string) --
The name of the global secondary index.
KeySchema (list) --
The complete key schema for the global secondary index, consisting of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexStatus (string) --
The current state of the global secondary index:
CREATING - The index is being created, as the result of a CreateTable or UpdateTable operation.
UPDATING - The index is being updated, as the result of a CreateTable or UpdateTable operation.
DELETING - The index is being deleted, as the result of a DeleteTable operation.
ACTIVE - The index is ready for use.
ProvisionedThroughput (dict) --
Represents the provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
Creates a new item, or replaces an old item with a new item. If an item that has the same primary key as the new item already exists in the specified table, the new item completely replaces the existing item. You can perform a conditional put operation (add a new item if one with the specified primary key doesn't exist), or replace an existing item if it has certain attribute values.
In addition to putting an item, you can also return the item's attribute values in the same operation, using the ReturnValues parameter.
When you add an item, the primary key attribute(s) are the only required attributes. Attribute values cannot be null. String and Binary type attributes must have lengths greater than zero. Set type attributes cannot be empty. Requests with empty values will be rejected with a ValidationException exception.
You can request that PutItem return either a copy of the original item (before the update) or a copy of the updated item (after the update). For more information, see the ReturnValues description below.
For more information about using this API, see Working with Items in the Amazon DynamoDB Developer Guide .
Request Syntax
client.put_item(
TableName='string',
Item={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
Expected={
'string': {
'Value': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
'Exists': True|False,
'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH',
'AttributeValueList': [
{
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
]
}
},
ReturnValues='NONE'|'ALL_OLD'|'UPDATED_OLD'|'ALL_NEW'|'UPDATED_NEW',
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
ReturnItemCollectionMetrics='SIZE'|'NONE',
ConditionalOperator='AND'|'OR',
ConditionExpression='string',
ExpressionAttributeNames={
'string': 'string'
},
ExpressionAttributeValues={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
)
string
[REQUIRED]
The name of the table to contain the item.
dict
[REQUIRED]
A map of attribute name/value pairs, one for each attribute. Only the primary key attributes are required; you can optionally provide other attribute name-value pairs for the item.
You must provide all of the attributes for the primary key. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide .
Each element in the Item map is an AttributeValue object.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use Expected and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A map of attribute/condition pairs. Expected provides a conditional block for the PutItem operation.
Each element of Expected consists of an attribute name, a comparison operator, and one or more values. DynamoDB compares the attribute with the value(s) you supplied, using the comparison operator. For each Expected element, the result of the evaluation is either true or false.
If you specify more than one element in the Expected map, then by default all of the conditions must evaluate to true. In other words, the conditions are ANDed together. (You can use the ConditionalOperator parameter to OR the conditions instead. If you do this, then at least one of the conditions must evaluate to true, rather than all of them.)
If the Expected map evaluates to true, then the conditional operation succeeds; otherwise, it fails.
Expected contains the following:
AttributeValueList - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used. For type Number, value comparisons are numeric. String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters. For type Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
ComparisonOperator - A comparator for evaluating attributes in the AttributeValueList . When performing the comparison, DynamoDB uses strongly consistent reads. The following comparison operators are available: EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
For backward compatibility with previous DynamoDB releases, the following parameters can be used instead of AttributeValueList and ComparisonOperator :
Value - A value for DynamoDB to compare with an attribute.
Exists - A Boolean value that causes DynamoDB to evaluate the value before attempting the conditional operation:
If Exists is true , DynamoDB will check to see if that attribute value already exists in the table. If it is found, then the condition evaluates to true; otherwise the condition evaluate to false.
If Exists is false , DynamoDB assumes that the attribute value does not exist in the table. If in fact the value does not exist, then the assumption is valid and the condition evaluates to true. If the value is found, despite the assumption that it does not exist, the condition evaluates to false.
The Value and Exists parameters are incompatible with AttributeValueList and ComparisonOperator . Note that if you use both sets of parameters at once, DynamoDB will return a ValidationException exception.
(string) --
(dict) --
Represents a condition to be compared with an attribute value. This condition can be used with DeleteItem , PutItem or UpdateItem operations; if the comparison evaluates to true, the operation succeeds; if not, the operation fails. You can use ExpectedAttributeValue in one of two different ways:
Use AttributeValueList to specify one or more values to compare against an attribute. Use ComparisonOperator to specify how you want to perform the comparison. If the comparison evaluates to true, then the conditional operation succeeds.
>Use Value to specify a value that DynamoDB will compare against an attribute. If the values match, then ExpectedAttributeValue evaluates to true and the conditional operation succeeds. Optionally, you can also set Exists to false, indicating that you do not expect to find the attribute value in the table. In this case, the conditional operation succeeds only if the comparison evaluates to false.
Value and Exists are incompatible with AttributeValueList and ComparisonOperator . Note that if you use both sets of parameters at once, DynamoDB will return a ValidationException exception.
Value (dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
Exists (boolean) --
Causes DynamoDB to evaluate the value before attempting a conditional operation:
If Exists is true , DynamoDB will check to see if that attribute value already exists in the table. If it is found, then the operation succeeds. If it is not found, the operation fails with a ConditionalCheckFailedException .
If Exists is false , DynamoDB assumes that the attribute value does not exist in the table. If in fact the value does not exist, then the assumption is valid and the operation succeeds. If the value is found, despite the assumption that it does not exist, the operation fails with a ConditionalCheckFailedException .
The default setting for Exists is true . If you supply a Value all by itself, DynamoDB assumes the attribute exists: You don't have to set Exists to true , because it is implied.
DynamoDB returns a ValidationException if:
Exists is true but there is no Value to check. (You expect a value to exist, but don't specify what that value is.)
Exists is false but you also specify a Value . (You cannot expect an attribute to have a value, while also expecting it not to exist.)
ComparisonOperator (string) --
A comparator for evaluating attributes in the AttributeValueList . For example, equals, greater than, less than, etc.
The following comparison operators are available:
EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN
The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
AttributeValueList (list) --
One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used.
For type Number, value comparisons are numeric.
String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters.
For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
For information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
string
Use ReturnValues if you want to get the item attributes as they appeared before they were updated with the PutItem request. For PutItem , the valid values are:
NONE - If ReturnValues is not specified, or if its value is NONE , then nothing is returned. (This setting is the default for ReturnValues .)
ALL_OLD - If PutItem overwrote an attribute name-value pair, then the content of the old item is returned.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
string
A value that if set to SIZE , the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.
string
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use ConditionalOperator and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A logical operator to apply to the conditions in the Expected map:
AND - If all of the conditions evaluate to true, then the entire map evaluates to true.
OR - If at least one of the conditions evaluate to true, then the entire map evaluates to true.
If you omit ConditionalOperator , then AND is the default.
The operation will succeed only if the entire map evaluates to true.
string
A condition that must be satisfied in order for a conditional PutItem operation to succeed.
An expression can contain any of the following:
Boolean functions: ATTRIBUTE_EXIST | CONTAINS | BEGINS_WITH
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: NOT | AND | OR
dict
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : character in an expression to dereference an attribute value. For example, consider the following expression:
ProductStatus IN ("Available","Backordered","Discontinued")
Now suppose that you specified the following for ExpressionAttributeValues :
{ "a":{"S":"Available"}, "b":{"S":"Backordered"}, "d":{"S":"Discontinued"} }
The expression can now be simplified as follows:
ProductStatus IN (:a,:b,:c)
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Response Syntax
{
'Attributes': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
},
'ItemCollectionMetrics': {
'ItemCollectionKey': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'SizeEstimateRangeGB': [
123.0,
]
}
}
Response Structure
(dict) --
Represents the output of a PutItem operation.
Attributes (dict) --
The attribute values as they appeared before the PutItem operation, but only if ReturnValues is specified as ALL_OLD in the request. Each element consists of an attribute name and an attribute value.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ConsumedCapacity (dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
ItemCollectionMetrics (dict) --
Information about item collections, if any, that were affected by the operation. ItemCollectionMetrics is only returned if the request asked for it. If the table does not have any local secondary indexes, this information is not returned in the response.
Each ItemCollectionMetrics element consists of:
ItemCollectionKey - The hash key value of the item collection. This is the same as the hash key of the item.
SizeEstimateRange - An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit. The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
ItemCollectionKey (dict) --
The hash key value of the item collection. This value is the same as the hash key of the item.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
SizeEstimateRangeGB (list) --
An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit.
The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
(float) --
A Query operation directly accesses items from a table using the table primary key, or from an index using the index key. You must provide a specific hash key value. You can narrow the scope of the query by using comparison operators on the range key value, or on the index key. You can use the ScanIndexForward parameter to get results in forward or reverse order, by range key or by index key.
Queries that do not return results consume the minimum number of read capacity units for that type of read operation.
If the total number of items meeting the query criteria exceeds the result set size limit of 1 MB, the query stops and results are returned to the user with LastEvaluatedKey to continue the query in a subsequent operation. Unlike a Scan operation, a Query operation never returns both an empty result set and a LastEvaluatedKey . The LastEvaluatedKey is only provided if the results exceed 1 MB, or if you have used Limit .
You can query a table, a local secondary index, or a global secondary index. For a query on a table or on a local secondary index, you can set ConsistentRead to true and obtain a strongly consistent result. Global secondary indexes support eventually consistent reads only, so do not specify ConsistentRead when querying a global secondary index.
Request Syntax
client.query(
TableName='string',
IndexName='string',
Select='ALL_ATTRIBUTES'|'ALL_PROJECTED_ATTRIBUTES'|'SPECIFIC_ATTRIBUTES'|'COUNT',
AttributesToGet=[
'string',
],
Limit=123,
ConsistentRead=True|False,
KeyConditions={
'string': {
'AttributeValueList': [
{
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
],
'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH'
}
},
QueryFilter={
'string': {
'AttributeValueList': [
{
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
],
'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH'
}
},
ConditionalOperator='AND'|'OR',
ScanIndexForward=True|False,
ExclusiveStartKey={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
ProjectionExpression='string',
FilterExpression='string',
ExpressionAttributeNames={
'string': 'string'
},
ExpressionAttributeValues={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
)
string
[REQUIRED]
The name of the table containing the requested items.
string
The name of an index to query. This index can be any local secondary index or global secondary index on the table.
string
The attributes to be returned in the result. You can retrieve all item attributes, specific item attributes, the count of matching items, or in the case of an index, some or all of the attributes projected into the index.
ALL_ATTRIBUTES - Returns all of the item attributes from the specified table or index. If you query a local secondary index, then for each matching item in the index DynamoDB will fetch the entire item from the parent table. If the index is configured to project all item attributes, then all of the data can be obtained from the local secondary index, and no fetching is required.
ALL_PROJECTED_ATTRIBUTES - Allowed only when querying an index. Retrieves all attributes that have been projected into the index. If the index is configured to project all attributes, this return value is equivalent to specifying ALL_ATTRIBUTES .
COUNT - Returns the number of matching items, rather than the matching items themselves.
SPECIFIC_ATTRIBUTES - Returns only the attributes listed in AttributesToGet . This return value is equivalent to specifying AttributesToGet without specifying any value for Select . If you query a local secondary index and request only attributes that are projected into that index, the operation will read only the index and not the table. If any of the requested attributes are not projected into the local secondary index, DynamoDB will fetch each of these attributes from the parent table. This extra fetching incurs additional throughput cost and latency. If you query a global secondary index, you can only request attributes that are projected into the index. Global secondary index queries cannot fetch attributes from the parent table.
If neither Select nor AttributesToGet are specified, DynamoDB defaults to ALL_ATTRIBUTES when accessing a table, and ALL_PROJECTED_ATTRIBUTES when accessing an index. You cannot use both Select and AttributesToGet together in a single request, unless the value for Select is SPECIFIC_ATTRIBUTES . (This usage is equivalent to specifying AttributesToGet without any value for Select .)
list
Warning
There is a newer parameter available. Use ProjectionExpression instead. Note that if you use AttributesToGet and ProjectionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter allows you to retrieve lists or maps; however, it cannot retrieve individual list or map elements.
The names of one or more attributes to retrieve. If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
Note that AttributesToGet has no effect on provisioned throughput consumption. DynamoDB determines capacity units consumed based on item size, not on the amount of data that is returned to an application.
You cannot use both AttributesToGet and Select together in a Query request, unless the value for Select is SPECIFIC_ATTRIBUTES . (This usage is equivalent to specifying AttributesToGet without any value for Select .)
If you query a local secondary index and request only attributes that are projected into that index, the operation will read only the index and not the table. If any of the requested attributes are not projected into the local secondary index, DynamoDB will fetch each of these attributes from the parent table. This extra fetching incurs additional throughput cost and latency.
If you query a global secondary index, you can only request attributes that are projected into the index. Global secondary index queries cannot fetch attributes from the parent table.
(string) --
integer
The maximum number of items to evaluate (not necessarily the number of matching items). If DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, and a key in LastEvaluatedKey to apply in a subsequent operation, so that you can pick up where you left off. Also, if the processed data set size exceeds 1 MB before DynamoDB reaches this limit, it stops the operation and returns the matching values up to the limit, and a key in LastEvaluatedKey to apply in a subsequent operation to continue the operation. For more information, see Query and Scan in the Amazon DynamoDB Developer Guide .
boolean
A value that if set to true , then the operation uses strongly consistent reads; otherwise, eventually consistent reads are used.
Strongly consistent reads are not supported on global secondary indexes. If you query a global secondary index with ConsistentRead set to true , you will receive an error message.
dict
[REQUIRED]
The selection criteria for the query. For a query on a table, you can have conditions only on the table primary key attributes. You must specify the hash key attribute name and value as an EQ condition. You can optionally specify a second condition, referring to the range key attribute.
For a query on an index, you can have conditions only on the index key attributes. You must specify the index hash attribute name and value as an EQ condition. You can optionally specify a second condition, referring to the index key range attribute.
Each KeyConditions element consists of an attribute name to compare, along with the following:
AttributeValueList - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used. For type Number, value comparisons are numeric. String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters. For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
ComparisonOperator - A comparator for evaluating attributes, for example, equals, greater than, less than, and so on. For KeyConditions , only the following comparison operators are supported: EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN The following are descriptions of these comparison operators.
EQ : Equal. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
(string) --
(dict) --
Represents the selection criteria for a Query or Scan operation:
For a Query operation, Condition is used for specifying the KeyConditions to use when querying a table or an index. For KeyConditions , only the following comparison operators are supported: EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN Condition is also used in a QueryFilter , which evaluates the query results and returns only the desired values.
For a Scan operation, Condition is used in a ScanFilter , which evaluates the scan results and returns only the desired values.
AttributeValueList (list) --
One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used.
For type Number, value comparisons are numeric.
String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters.
For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ComparisonOperator (string) -- [REQUIRED]
A comparator for evaluating attributes. For example, equals, greater than, less than, etc.
The following comparison operators are available:
EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN
The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
dict
Warning
There is a newer parameter available. Use FilterExpression instead. Note that if you use QueryFilter and FilterExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A condition that evaluates the query results and returns only the desired values.
If you specify more than one condition in the QueryFilter map, then by default all of the conditions must evaluate to true. In other words, the conditions are ANDed together. (You can use the ConditionalOperator parameter to OR the conditions instead. If you do this, then at least one of the conditions must evaluate to true, rather than all of them.)
Each QueryFilter element consists of an attribute name to compare, along with the following:
AttributeValueList - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the operator specified in ComparisonOperator . For type Number, value comparisons are numeric. String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters. For type Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions. For information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
ComparisonOperator - A comparator for evaluating attributes. For example, equals, greater than, less than, etc. The following comparison operators are available: EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN For complete descriptions of all comparison operators, see API_Condition.html.
(string) --
(dict) --
Represents the selection criteria for a Query or Scan operation:
For a Query operation, Condition is used for specifying the KeyConditions to use when querying a table or an index. For KeyConditions , only the following comparison operators are supported: EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN Condition is also used in a QueryFilter , which evaluates the query results and returns only the desired values.
For a Scan operation, Condition is used in a ScanFilter , which evaluates the scan results and returns only the desired values.
AttributeValueList (list) --
One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used.
For type Number, value comparisons are numeric.
String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters.
For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ComparisonOperator (string) -- [REQUIRED]
A comparator for evaluating attributes. For example, equals, greater than, less than, etc.
The following comparison operators are available:
EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN
The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
string
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use ConditionalOperator and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A logical operator to apply to the conditions in the QueryFilter map:
AND - If all of the conditions evaluate to true, then the entire map evaluates to true.
OR - If at least one of the conditions evaluate to true, then the entire map evaluates to true.
If you omit ConditionalOperator , then AND is the default.
The operation will succeed only if the entire map evaluates to true.
boolean
A value that specifies ascending (true) or descending (false) traversal of the index. DynamoDB returns results reflecting the requested order determined by the range key. If the data type is Number, the results are returned in numeric order. For type String, the results are returned in order of ASCII character code values. For type Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values.
If ScanIndexForward is not specified, the results are returned in ascending order.
dict
The primary key of the first item that this operation will evaluate. Use the value that was returned for LastEvaluatedKey in the previous operation.
The data type for ExclusiveStartKey must be String, Number or Binary. No set data types are allowed.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
string
One or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.
If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
string
A condition that evaluates the query results and returns only the desired values.
The condition you specify is applied to the items queried; any items that do not match the expression are not returned.
dict
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : character in an expression to dereference an attribute value. For example, consider the following expression:
ProductStatus IN ("Available","Backordered","Discontinued")
Now suppose that you specified the following for ExpressionAttributeValues :
{ "a":{"S":"Available"}, "b":{"S":"Backordered"}, "d":{"S":"Discontinued"} }
The expression can now be simplified as follows:
ProductStatus IN (:a,:b,:c)
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Response Syntax
{
'Items': [
{
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
],
'Count': 123,
'ScannedCount': 123,
'LastEvaluatedKey': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
}
}
Response Structure
(dict) --
Represents the output of a Query operation.
Items (list) --
An array of item attributes that match the query criteria. Each element in this array consists of an attribute name and the value for that attribute.
(dict) --
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
Count (integer) --
The number of items in the response.
If you used a QueryFilter in the request, then Count is the number of items returned after the filter was applied, and ScannedCount is the number of matching items before> the filter was applied.
If you did not use a filter in the request, then Count and ScannedCount are the same.
ScannedCount (integer) --
The number of items evaluated, before any QueryFilter is applied. A high ScannedCount value with few, or no, Count results indicates an inefficient Query operation. For more information, see Count and ScannedCount in the Amazon DynamoDB Developer Guide .
If you did not use a filter in the request, then ScannedCount is the same as Count .
LastEvaluatedKey (dict) --
The primary key of the item where the operation stopped, inclusive of the previous result set. Use this value to start a new operation, excluding this value in the new request.
If LastEvaluatedKey is empty, then the "last page" of results has been processed and there is no more data to be retrieved.
If LastEvaluatedKey is not empty, it does not necessarily mean that there is more data in the result set. The only way to know when you have reached the end of the result set is when LastEvaluatedKey is empty.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ConsumedCapacity (dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
Returns an array of table names associated with the current account and endpoint. The output from ListTables is paginated, with each page returning a maximum of 100 table names.
Request Syntax
client.list_tables(
ExclusiveStartTableName='string',
Limit=123
)
string
The first table name that this operation will evaluate. Use the value that was returned for LastEvaluatedTableName in a previous operation, so that you can obtain the next page of results.
integer
A maximum number of table names to return. If this parameter is not specified, the limit is 100.
dict
Response Syntax
{
'TableNames': [
'string',
],
'LastEvaluatedTableName': 'string'
}
Response Structure
(dict) --
Represents the output of a ListTables operation.
TableNames (list) --
The names of the tables associated with the current account at the current endpoint. The maximum size of this array is 100.
If LastEvaluatedTableName also appears in the output, you can use this value as the ExclusiveStartTableName parameter in a subsequent ListTables request and obtain the next page of results.
(string) --
LastEvaluatedTableName (string) --
The name of the last table in the current page of results. Use this value as the ExclusiveStartTableName in a new request to obtain the next page of results, until all the table names are returned.
If you do not receive a LastEvaluatedTableName value in the response, this means that there are no more table names to be retrieved.
The DeleteTable operation deletes a table and all of its items. After a DeleteTable request, the specified table is in the DELETING state until DynamoDB completes the deletion. If the table is in the ACTIVE state, you can delete it. If a table is in CREATING or UPDATING states, then DynamoDB returns a ResourceInUseException . If the specified table does not exist, DynamoDB returns a ResourceNotFoundException . If table is already in the DELETING state, no error is returned.
When you delete a table, any indexes on that table are also deleted.
Use the DescribeTable API to check the status of the table.
Request Syntax
client.delete_table(
TableName='string'
)
string
[REQUIRED]
The name of the table to delete.
dict
Response Syntax
{
'TableDescription': {
'AttributeDefinitions': [
{
'AttributeName': 'string',
'AttributeType': 'S'|'N'|'B'
},
],
'TableName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'TableStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'CreationDateTime': datetime(2015, 1, 1),
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'TableSizeBytes': 123,
'ItemCount': 123,
'LocalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
],
'GlobalSecondaryIndexes': [
{
'IndexName': 'string',
'KeySchema': [
{
'AttributeName': 'string',
'KeyType': 'HASH'|'RANGE'
},
],
'Projection': {
'ProjectionType': 'ALL'|'KEYS_ONLY'|'INCLUDE',
'NonKeyAttributes': [
'string',
]
},
'IndexStatus': 'CREATING'|'UPDATING'|'DELETING'|'ACTIVE',
'ProvisionedThroughput': {
'LastIncreaseDateTime': datetime(2015, 1, 1),
'LastDecreaseDateTime': datetime(2015, 1, 1),
'NumberOfDecreasesToday': 123,
'ReadCapacityUnits': 123,
'WriteCapacityUnits': 123
},
'IndexSizeBytes': 123,
'ItemCount': 123
},
]
}
}
Response Structure
(dict) --
Represents the output of a DeleteTable operation.
TableDescription (dict) --
Represents the properties of a table.
AttributeDefinitions (list) --
An array of AttributeDefinition objects. Each of these objects describes one attribute in the table and index key schema.
Each AttributeDefinition object in this array is composed of:
AttributeName - The name of the attribute.
AttributeType - The data type for the attribute.
(dict) --
Represents an attribute for describing the key schema for the table and indexes.
AttributeName (string) --
A name for the attribute.
AttributeType (string) --
The data type for the attribute.
TableName (string) --
The name of the table.
KeySchema (list) --
The primary key structure for the table. Each KeySchemaElement consists of:
AttributeName - The name of the attribute.
KeyType - The key type for the attribute. Can be either HASH or RANGE .
For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide .
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
TableStatus (string) --
The current state of the table:
CREATING - The table is being created, as the result of a CreateTable operation.
UPDATING - The table is being updated, as the result of an UpdateTable operation.
DELETING - The table is being deleted, as the result of a DeleteTable operation.
ACTIVE - The table is ready for use.
CreationDateTime (datetime) --
The date and time when the table was created, in UNIX epoch time format.
ProvisionedThroughput (dict) --
The provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
TableSizeBytes (integer) --
The total size of the specified table, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified table. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
LocalSecondaryIndexes (list) --
Represents one or more local secondary indexes on the table. Each index is scoped to a given hash key value. Tables with one or more local secondary indexes are subject to an item collection size limit, where the amount of data within a given item collection cannot exceed 10 GB. Each element is composed of:
IndexName - The name of the local secondary index.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
IndexSizeBytes - Represents the total size of the index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount - Represents the number of items in the index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a local secondary index.
IndexName (string) --
Represents the name of the local secondary index.
KeySchema (list) --
The complete index key schema, which consists of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
GlobalSecondaryIndexes (list) --
The global secondary indexes, if any, on the table. Each index is scoped to a given hash key value. Each element is composed of:
IndexName - The name of the global secondary index.
IndexSizeBytes - The total size of the global secondary index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
IndexStatus - The current status of the global secondary index:
CREATING - The index is being created.
UPDATING - The index is being updated.
DELETING - The index is being deleted.
ACTIVE - The index is ready for use.
ItemCount - The number of items in the global secondary index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same hash key attribute as the table.
Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:
ProjectionType - One of the following:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes specified in NonKeyAttributes , summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
ProvisionedThroughput - The provisioned throughput settings for the global secondary index, consisting of read and write capacity units, along with data about increases and decreases.
If the table is in the DELETING state, no information about indexes will be returned.
(dict) --
Represents the properties of a global secondary index.
IndexName (string) --
The name of the global secondary index.
KeySchema (list) --
The complete key schema for the global secondary index, consisting of one or more pairs of attribute names and key types ( HASH or RANGE ).
(dict) --
Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.
A KeySchemaElement represents exactly one attribute of the primary key. For example, a hash type primary key would be represented by one KeySchemaElement . A hash-and-range type primary key would require one KeySchemaElement for the hash attribute, and another KeySchemaElement for the range attribute.
AttributeName (string) --
The name of a key attribute.
KeyType (string) --
The attribute data, consisting of the data type and the attribute value itself.
Projection (dict) --
Represents attributes that are copied (projected) from the table into an index. These are in addition to the primary key attributes and index key attributes, which are automatically projected.
ProjectionType (string) --
The set of attributes that are projected into the index:
KEYS_ONLY - Only the index and primary keys are projected into the index.
INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes are in NonKeyAttributes .
ALL - All of the table attributes are projected into the index.
NonKeyAttributes (list) --
Represents the non-key attribute names which will be projected into the index.
For local secondary indexes, the total count of NonKeyAttributes summed across all of the local secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.
(string) --
IndexStatus (string) --
The current state of the global secondary index:
CREATING - The index is being created, as the result of a CreateTable or UpdateTable operation.
UPDATING - The index is being updated, as the result of a CreateTable or UpdateTable operation.
DELETING - The index is being deleted, as the result of a DeleteTable operation.
ACTIVE - The index is ready for use.
ProvisionedThroughput (dict) --
Represents the provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.
LastIncreaseDateTime (datetime) --
The date and time of the last provisioned throughput increase for this table.
LastDecreaseDateTime (datetime) --
The date and time of the last provisioned throughput decrease for this table.
NumberOfDecreasesToday (integer) --
The number of provisioned throughput decreases for this table during this UTC calendar day. For current maximums on provisioned throughput decreases, see Limits in the Amazon DynamoDB Developer Guide .
ReadCapacityUnits (integer) --
The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException . Eventually consistent reads require less effort than strongly consistent reads, so a setting of 50 ReadCapacityUnits per second provides 100 eventually consistent ReadCapacityUnits per second.
WriteCapacityUnits (integer) --
The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException .
IndexSizeBytes (integer) --
The total size of the specified index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
ItemCount (integer) --
The number of items in the specified index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.
The GetItem operation returns a set of attributes for the item with the given primary key. If there is no matching item, GetItem does not return any data.
GetItem provides an eventually consistent read by default. If your application requires a strongly consistent read, set ConsistentRead to true . Although a strongly consistent read might take more time than an eventually consistent read, it always returns the last updated value.
Request Syntax
client.get_item(
TableName='string',
Key={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
AttributesToGet=[
'string',
],
ConsistentRead=True|False,
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
ProjectionExpression='string',
ExpressionAttributeNames={
'string': 'string'
}
)
string
[REQUIRED]
The name of the table containing the requested item.
dict
[REQUIRED]
A map of attribute names to AttributeValue objects, representing the primary key of the item to retrieve.
For the primary key, you must provide all of the attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
list
Warning
There is a newer parameter available. Use ProjectionExpression instead. Note that if you use AttributesToGet and ProjectionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter allows you to retrieve lists or maps; however, it cannot retrieve individual list or map elements.
The names of one or more attributes to retrieve. If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
Note that AttributesToGet has no effect on provisioned throughput consumption. DynamoDB determines capacity units consumed based on item size, not on the amount of data that is returned to an application.
(string) --
boolean
A value that if set to true , then the operation uses strongly consistent reads; otherwise, eventually consistent reads are used.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
string
One or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.
If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.
dict
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
dict
Response Syntax
{
'Item': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
}
}
Response Structure
(dict) --
Represents the output of a GetItem operation.
Item (dict) --
A map of attribute names to AttributeValue objects, as specified by AttributesToGet .
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ConsumedCapacity (dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
Deletes a single item in a table by primary key. You can perform a conditional delete operation that deletes the item if it exists, or if it has an expected attribute value.
In addition to deleting an item, you can also return the item's attribute values in the same operation, using the ReturnValues parameter.
Unless you specify conditions, the DeleteItem is an idempotent operation; running it multiple times on the same item or attribute does not result in an error response.
Conditional deletes are useful for deleting items only if specific conditions are met. If those conditions are met, DynamoDB performs the delete. Otherwise, the item is not deleted.
Request Syntax
client.delete_item(
TableName='string',
Key={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
Expected={
'string': {
'Value': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
'Exists': True|False,
'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH',
'AttributeValueList': [
{
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
},
]
}
},
ConditionalOperator='AND'|'OR',
ReturnValues='NONE'|'ALL_OLD'|'UPDATED_OLD'|'ALL_NEW'|'UPDATED_NEW',
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
ReturnItemCollectionMetrics='SIZE'|'NONE',
ConditionExpression='string',
ExpressionAttributeNames={
'string': 'string'
},
ExpressionAttributeValues={
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
}
)
string
[REQUIRED]
The name of the table from which to delete the item.
dict
[REQUIRED]
A map of attribute names to AttributeValue objects, representing the primary key of the item to delete.
For the primary key, you must provide all of the attributes. For example, with a hash type primary key, you only need to specify the hash attribute. For a hash-and-range type primary key, you must specify both the hash attribute and the range attribute.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use Expected and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A map of attribute/condition pairs. Expected provides a conditional block for the DeleteItem operation.
Each element of Expected consists of an attribute name, a comparison operator, and one or more values. DynamoDB compares the attribute with the value(s) you supplied, using the comparison operator. For each Expected element, the result of the evaluation is either true or false.
If you specify more than one element in the Expected map, then by default all of the conditions must evaluate to true. In other words, the conditions are ANDed together. (You can use the ConditionalOperator parameter to OR the conditions instead. If you do this, then at least one of the conditions must evaluate to true, rather than all of them.)
If the Expected map evaluates to true, then the conditional operation succeeds; otherwise, it fails.
Expected contains the following:
AttributeValueList - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used. For type Number, value comparisons are numeric. String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters. For type Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
ComparisonOperator - A comparator for evaluating attributes in the AttributeValueList . When performing the comparison, DynamoDB uses strongly consistent reads. The following comparison operators are available: EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
For usage examples of AttributeValueList and ComparisonOperator , see Legacy Conditional Parameters in the Amazon DynamoDB Developer Guide .
For backward compatibility with previous DynamoDB releases, the following parameters can be used instead of AttributeValueList and ComparisonOperator :
Value - A value for DynamoDB to compare with an attribute.
Exists - A Boolean value that causes DynamoDB to evaluate the value before attempting the conditional operation:
If Exists is true , DynamoDB will check to see if that attribute value already exists in the table. If it is found, then the condition evaluates to true; otherwise the condition evaluate to false.
If Exists is false , DynamoDB assumes that the attribute value does not exist in the table. If in fact the value does not exist, then the assumption is valid and the condition evaluates to true. If the value is found, despite the assumption that it does not exist, the condition evaluates to false.
The Value and Exists parameters are incompatible with AttributeValueList and ComparisonOperator . Note that if you use both sets of parameters at once, DynamoDB will return a ValidationException exception.
(string) --
(dict) --
Represents a condition to be compared with an attribute value. This condition can be used with DeleteItem , PutItem or UpdateItem operations; if the comparison evaluates to true, the operation succeeds; if not, the operation fails. You can use ExpectedAttributeValue in one of two different ways:
Use AttributeValueList to specify one or more values to compare against an attribute. Use ComparisonOperator to specify how you want to perform the comparison. If the comparison evaluates to true, then the conditional operation succeeds.
>Use Value to specify a value that DynamoDB will compare against an attribute. If the values match, then ExpectedAttributeValue evaluates to true and the conditional operation succeeds. Optionally, you can also set Exists to false, indicating that you do not expect to find the attribute value in the table. In this case, the conditional operation succeeds only if the comparison evaluates to false.
Value and Exists are incompatible with AttributeValueList and ComparisonOperator . Note that if you use both sets of parameters at once, DynamoDB will return a ValidationException exception.
Value (dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
Exists (boolean) --
Causes DynamoDB to evaluate the value before attempting a conditional operation:
If Exists is true , DynamoDB will check to see if that attribute value already exists in the table. If it is found, then the operation succeeds. If it is not found, the operation fails with a ConditionalCheckFailedException .
If Exists is false , DynamoDB assumes that the attribute value does not exist in the table. If in fact the value does not exist, then the assumption is valid and the operation succeeds. If the value is found, despite the assumption that it does not exist, the operation fails with a ConditionalCheckFailedException .
The default setting for Exists is true . If you supply a Value all by itself, DynamoDB assumes the attribute exists: You don't have to set Exists to true , because it is implied.
DynamoDB returns a ValidationException if:
Exists is true but there is no Value to check. (You expect a value to exist, but don't specify what that value is.)
Exists is false but you also specify a Value . (You cannot expect an attribute to have a value, while also expecting it not to exist.)
ComparisonOperator (string) --
A comparator for evaluating attributes in the AttributeValueList . For example, equals, greater than, less than, etc.
The following comparison operators are available:
EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN
The following are descriptions of each comparison operator.
EQ : Equal. EQ is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
NE : Not equal. NE is supported for all datatypes, including lists and maps. AttributeValueList can contain only one AttributeValue of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an AttributeValue of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not equal {"NS":["6", "2", "1"]} .
LE : Less than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
LT : Less than. AttributeValueList can contain only one AttributeValue of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GE : Greater than or equal. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
GT : Greater than. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not equal {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]} .
NOT_NULL : The attribute exists. NOT_NULL is supported for all datatypes, including lists and maps.
NULL : The attribute does not exist. NULL is supported for all datatypes, including lists and maps.
CONTAINS : Checks for a subsequence, or value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " a CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
NOT_CONTAINS : Checks for absence of a subsequence, or absence of a value in a set. AttributeValueList can contain only one AttributeValue element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" SS ", " NS ", or " BS "), then the operator evaluates to true if it does not find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " a NOT CONTAINS b ", " a " can be a list; however, " b " cannot be a set, a map, or a list.
BEGINS_WITH : Checks for a prefix. AttributeValueList can contain only one AttributeValue of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
IN : Checks for matching elements within two sets. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary (not a set type). These attributes are compared against an existing set type attribute of an item. If any elements of the input set are present in the item attribute, the expression evaluates to true.
BETWEEN : Greater than or equal to the first value, and less than or equal to the second value. AttributeValueList must contain two AttributeValue elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an AttributeValue element of a different type than the one specified in the request, the value does not match. For example, {"S":"6"} does not compare to {"N":"6"} . Also, {"N":"6"} does not compare to {"NS":["6", "2", "1"]}
AttributeValueList (list) --
One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ComparisonOperator being used.
For type Number, value comparisons are numeric.
String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, a is greater than A , and aa is greater than B . For a list of code values, see http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters.
For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values, for example when evaluating query expressions.
For information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
string
Warning
There is a newer parameter available. Use ConditionExpression instead. Note that if you use ConditionalOperator and ConditionExpression at the same time, DynamoDB will return a ValidationException exception.
This parameter does not support lists or maps.
A logical operator to apply to the conditions in the Expected map:
AND - If all of the conditions evaluate to true, then the entire map evaluates to true.
OR - If at least one of the conditions evaluate to true, then the entire map evaluates to true.
If you omit ConditionalOperator , then AND is the default.
The operation will succeed only if the entire map evaluates to true.
string
Use ReturnValues if you want to get the item attributes as they appeared before they were deleted. For DeleteItem , the valid values are:
NONE - If ReturnValues is not specified, or if its value is NONE , then nothing is returned. (This setting is the default for ReturnValues .)
ALL_OLD - The content of the old item is returned.
string
A value that if set to TOTAL , the response includes ConsumedCapacity data for tables and indexes. If set to INDEXES , the response includes ConsumedCapacity for indexes. If set to NONE (the default), ConsumedCapacity is not included in the response.
string
A value that if set to SIZE , the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.
string
A condition that must be satisfied in order for a conditional DeleteItem to succeed.
An expression can contain any of the following:
Boolean functions: ATTRIBUTE_EXIST | CONTAINS | BEGINS_WITH
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: NOT | AND | OR
dict
One or more substitution tokens for simplifying complex expressions. The following are some use cases for an ExpressionAttributeNames value:
To shorten an attribute name that is very long or unwieldy in an expression.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following expression:
order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName = "Jones"
Now suppose that you specified the following for ExpressionAttributeNames :
{"n":"order.customerInfo.LastName"}
The expression can now be simplified as follows:
#n = "Smith" OR #n = "Jones"
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : character in an expression to dereference an attribute value. For example, consider the following expression:
ProductStatus IN ("Available","Backordered","Discontinued")
Now suppose that you specified the following for ExpressionAttributeValues :
{ "a":{"S":"Available"}, "b":{"S":"Backordered"}, "d":{"S":"Discontinued"} }
The expression can now be simplified as follows:
ProductStatus IN (:a,:b,:c)
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
dict
Response Syntax
{
'Attributes': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'Table': {
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'CapacityUnits': 123.0
}
}
},
'ItemCollectionMetrics': {
'ItemCollectionKey': {
'string': {
'S': 'string',
'N': 'string',
'B': b'bytes',
'SS': [
'string',
],
'NS': [
'string',
],
'BS': [
b'bytes',
],
'M': {
'string': {'... recursive ...'}
},
'L': [
{'... recursive ...'},
],
'NULL': True|False,
'BOOL': True|False
}
},
'SizeEstimateRangeGB': [
123.0,
]
}
}
Response Structure
(dict) --
Represents the output of a DeleteItem operation.
Attributes (dict) --
A map of attribute names to AttributeValue objects, representing the item as it appeared before the DeleteItem operation. This map appears in the response only if ReturnValues was specified as ALL_OLD in the request.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
ConsumedCapacity (dict) --
The capacity units consumed by an operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the request asked for it. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .
TableName (string) --
The name of the table that was affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
LocalSecondaryIndexes (dict) --
The amount of throughput consumed on each local index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
GlobalSecondaryIndexes (dict) --
The amount of throughput consumed on each global index affected by the operation.
(string) --
(dict) --
Represents the amount of provisioned throughput capacity consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
ItemCollectionMetrics (dict) --
Information about item collections, if any, that were affected by the operation. ItemCollectionMetrics is only returned if the request asked for it. If the table does not have any local secondary indexes, this information is not returned in the response.
Each ItemCollectionMetrics element consists of:
ItemCollectionKey - The hash key value of the item collection. This is the same as the hash key of the item.
SizeEstimateRange - An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit. The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
ItemCollectionKey (dict) --
The hash key value of the item collection. This value is the same as the hash key of the item.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
S (string) --
A String data type.
N (string) --
A Number data type.
B (bytes) --
A Binary data type.
SS (list) --
A String Set data type.
(string) --
NS (list) --
A Number Set data type.
(string) --
BS (list) --
A Binary Set data type.
(bytes) --
M (dict) --
A Map of attribute values.
(string) --
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
L (list) --
A List of attribute values.
(dict) --
Represents the data for an attribute. You can set one, and only one, of the elements.
Each attribute in an item is a name-value pair. An attribute can be single-valued or multi-valued set. For example, a book item can have title and authors attributes. Each book has one title but can have many authors. The multi-valued attribute is a set; duplicate values are not allowed.
NULL (boolean) --
A Null data type.
BOOL (boolean) --
A Boolean data type.
SizeEstimateRangeGB (list) --
An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit.
The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
(float) --