2023/06/29 - Amazon DynamoDB - 6 updated api methods
Changes This release adds ReturnValuesOnConditionCheckFailure parameter to PutItem, UpdateItem, DeleteItem, ExecuteStatement, BatchExecuteStatement and ExecuteTransaction APIs. When set to ALL_OLD, API returns a copy of the item as it was when a conditional write failed
{'Statements': {'ReturnValuesOnConditionCheckFailure': 'ALL_OLD | NONE'}}
Response {'Responses': {'Error': {'Item': {'string': {'B': 'blob',
'BOOL': 'boolean',
'BS': ['blob'],
'L': [()],
'M': {'string': ()},
'N': 'string',
'NS': ['string'],
'NULL': 'boolean',
'S': 'string',
'SS': ['string']}}}}}
This operation allows you to perform batch reads or writes on data stored in DynamoDB, using PartiQL. Each read statement in a BatchExecuteStatement must specify an equality condition on all key attributes. This enforces that each SELECT statement in a batch returns at most a single item.
Note
The entire batch must consist of either read statements or write statements, you cannot mix both in one batch.
Warning
A HTTP 200 response does not mean that all statements in the BatchExecuteStatement succeeded. Error details for individual statements can be found under the Error field of the BatchStatementResponse for each statement.
See also: AWS API Documentation
Request Syntax
client.batch_execute_statement(
Statements=[
{
'Statement': 'string',
'Parameters': [
{
'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
},
],
'ConsistentRead': True|False,
'ReturnValuesOnConditionCheckFailure': 'ALL_OLD'|'NONE'
},
],
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE'
)
list
[REQUIRED]
The list of PartiQL statements representing the batch to run.
(dict) --
A PartiQL batch statement request.
Statement (string) -- [REQUIRED]
A valid PartiQL statement.
Parameters (list) --
The parameters associated with a PartiQL statement in the batch request.
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ConsistentRead (boolean) --
The read consistency of the PartiQL batch request.
ReturnValuesOnConditionCheckFailure (string) --
An optional parameter that returns the item attributes for a PartiQL batch request operation that failed a condition check.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
string
Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:
INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
NONE - No ConsumedCapacity details are included in the response.
dict
Response Syntax
{
'Responses': [
{
'Error': {
'Code': 'ConditionalCheckFailed'|'ItemCollectionSizeLimitExceeded'|'RequestLimitExceeded'|'ValidationError'|'ProvisionedThroughputExceeded'|'TransactionConflict'|'ThrottlingError'|'InternalServerError'|'ResourceNotFound'|'AccessDenied'|'DuplicateItem',
'Message': '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
}
}
},
'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
}
}
},
],
'ConsumedCapacity': [
{
'TableName': 'string',
'CapacityUnits': 123.0,
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'Table': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
}
},
]
}
Response Structure
(dict) --
Responses (list) --
The response to each PartiQL statement in the batch.
(dict) --
A PartiQL batch statement response..
Error (dict) --
The error associated with a failed PartiQL batch statement.
Code (string) --
The error code associated with the failed PartiQL batch statement.
Message (string) --
The error message associated with the PartiQL batch response.
Item (dict) --
The item which caused the condition check to fail. This will be set if ReturnValuesOnConditionCheckFailure is specified as ALL_OLD .
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
TableName (string) --
The table name associated with a failed PartiQL batch statement.
Item (dict) --
A DynamoDB item associated with a BatchStatementResponse
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ConsumedCapacity (list) --
The capacity units consumed by the entire operation. The values of the list are ordered according to the ordering of the statements.
(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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed by the operation.
WriteCapacityUnits (float) --
The total number of write capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
{'ReturnValuesOnConditionCheckFailure': 'ALL_OLD | NONE'}
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.
See also: AWS API Documentation
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
}
},
ReturnValuesOnConditionCheckFailure='ALL_OLD'|'NONE'
)
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 key attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
dict
This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide .
(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 the expected attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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 ConditionCheckFailedException .
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 ConditionCheckFailedException .
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 provide 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 data types, 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 provided 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 data types, 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 provided 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 provided 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 provided 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 provided 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 provided 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 data types, including lists and maps.
Note
This operator tests for the existence of an attribute, not its data type. If the data type of attribute " a " is null, and you evaluate it using NOT_NULL , the result is a Boolean true . This result is because the attribute " a " exists; its data type is not relevant to the NOT_NULL comparison operator.
NULL : The attribute does not exist. NULL is supported for all data types, including lists and maps.
Note
This operator tests for the nonexistence of an attribute, not its data type. If the data type of attribute " a " is null, and you evaluate it using NULL , the result is a Boolean false . This is because the attribute " a " exists; its data type is not relevant to the NULL comparison operator.
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 in a list. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary. These attributes are compared against an existing attribute of an item. If any elements of the input are equal to 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 provided 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 a 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 information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
string
This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide .
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.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
Note
The ReturnValues parameter is used by several DynamoDB operations; however, DeleteItem does not recognize any values other than NONE or ALL_OLD .
string
Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:
INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
NONE - No ConsumedCapacity details are included in the response.
string
Determines whether item collection metrics are returned. 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:
Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size These function names are case-sensitive.
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: AND | OR | NOT
For more information about condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide .
dict
One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames :
To access an attribute whose name conflicts with a DynamoDB reserved word.
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 attribute name:
Percentile
The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide ). To work around this, you could specify the following for ExpressionAttributeNames :
{"#P":"Percentile"}
You could then use this substitution in an expression, as in this example:
#P = :val
Note
Tokens that begin with the : character are expression attribute values , which are placeholders for the actual value at runtime.
For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide .
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:
Available | Backordered | Discontinued
You would first need to specify ExpressionAttributeValues as follows:
{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }
You could then use these values in an expression, such as this:
ProductStatus IN (:avail, :back, :disc)
For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide .
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
string
An optional parameter that returns the item attributes for a DeleteItem operation that failed a condition check.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
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,
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'Table': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'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.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ConsumedCapacity (dict) --
The capacity units consumed by the DeleteItem 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 ReturnConsumedCapacity parameter was specified. 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed by the operation.
WriteCapacityUnits (float) --
The total number of write capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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 DeleteItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. 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 partition key value of the item collection. This is the same as the partition key value of the item itself.
SizeEstimateRangeGB - 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 partition key value of the item collection. This value is the same as the partition key value of the item.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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) --
{'ReturnValuesOnConditionCheckFailure': 'ALL_OLD | NONE'}
This operation allows you to perform reads and singleton writes on data stored in DynamoDB, using PartiQL.
For PartiQL reads ( SELECT statement), if the total number of processed items exceeds the maximum dataset size limit of 1 MB, the read stops and results are returned to the user as a LastEvaluatedKey value to continue the read in a subsequent operation. If the filter criteria in WHERE clause does not match any data, the read will return an empty result set.
A single SELECT statement response can return up to the maximum number of items (if using the Limit parameter) or a maximum of 1 MB of data (and then apply any filtering to the results using WHERE clause). If LastEvaluatedKey is present in the response, you need to paginate the result set. If NextToken is present, you need to paginate the result set and include NextToken .
See also: AWS API Documentation
Request Syntax
client.execute_statement(
Statement='string',
Parameters=[
{
'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
},
],
ConsistentRead=True|False,
NextToken='string',
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
Limit=123,
ReturnValuesOnConditionCheckFailure='ALL_OLD'|'NONE'
)
string
[REQUIRED]
The PartiQL statement representing the operation to run.
list
The parameters for the PartiQL statement, if any.
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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.
string
Set this value to get remaining results, if NextToken was returned in the statement response.
string
Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:
INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
NONE - No ConsumedCapacity details are included in the response.
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, along with a key in LastEvaluatedKey to apply in a subsequent operation so you can pick up where you left off. Also, if the processed dataset 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.
string
An optional parameter that returns the item attributes for an ExecuteStatement operation that failed a condition check.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
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
}
},
],
'NextToken': 'string',
'ConsumedCapacity': {
'TableName': 'string',
'CapacityUnits': 123.0,
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'Table': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
}
},
'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
}
}
}
Response Structure
(dict) --
Items (list) --
If a read operation was used, this property will contain the result of the read operation; a map of attribute names and their values. For the write operations this value will be empty.
(dict) --
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
NextToken (string) --
If the response of a read request exceeds the response payload limit DynamoDB will set this value in the response. If set, you can use that this value in the subsequent request to get the remaining results.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed by the operation.
WriteCapacityUnits (float) --
The total number of write capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
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.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
{'TransactStatements': {'ReturnValuesOnConditionCheckFailure': 'ALL_OLD | '
'NONE'}}
This operation allows you to perform transactional reads or writes on data stored in DynamoDB, using PartiQL.
Note
The entire transaction must consist of either read statements or write statements, you cannot mix both in one transaction. The EXISTS function is an exception and can be used to check the condition of specific attributes of the item in a similar manner to ConditionCheck in the TransactWriteItems API.
See also: AWS API Documentation
Request Syntax
client.execute_transaction(
TransactStatements=[
{
'Statement': 'string',
'Parameters': [
{
'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
},
],
'ReturnValuesOnConditionCheckFailure': 'ALL_OLD'|'NONE'
},
],
ClientRequestToken='string',
ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE'
)
list
[REQUIRED]
The list of PartiQL statements representing the transaction to run.
(dict) --
Represents a PartiQL statment that uses parameters.
Statement (string) -- [REQUIRED]
A PartiQL statment that uses parameters.
Parameters (list) --
The parameter values.
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ReturnValuesOnConditionCheckFailure (string) --
An optional parameter that returns the item attributes for a PartiQL ParameterizedStatement operation that failed a condition check.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
string
Set this value to get remaining results, if NextToken was returned in the statement response.
This field is autopopulated if not provided.
string
Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response. For more information, see TransactGetItems and TransactWriteItems.
dict
Response Syntax
{
'Responses': [
{
'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,
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'Table': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
}
},
]
}
Response Structure
(dict) --
Responses (list) --
The response to a PartiQL transaction.
(dict) --
Details for the requested item.
Item (dict) --
Map of attribute data consisting of the data type and attribute value.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ConsumedCapacity (list) --
The capacity units consumed by the entire operation. The values of the list are ordered according to the ordering of the statements.
(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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed by the operation.
WriteCapacityUnits (float) --
The total number of write capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
CapacityUnits (float) --
The total number of capacity units consumed on a table or an index.
{'ReturnValuesOnConditionCheckFailure': 'ALL_OLD | NONE'}
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. You can return the item's attribute values in the same operation, using the ReturnValues parameter.
When you add an item, the primary key attributes are the only required attributes.
Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index. Set type attributes cannot be empty.
Invalid Requests with empty values will be rejected with a ValidationException exception.
Note
To prevent a new item from replacing an existing item, use a conditional expression that contains the attribute_not_exists function with the name of the attribute being used as the partition key for the table. Since every record must contain that attribute, the attribute_not_exists function will only succeed if no matching item exists.
For more information about PutItem , see Working with Items in the Amazon DynamoDB Developer Guide .
See also: AWS API Documentation
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
}
},
ReturnValuesOnConditionCheckFailure='ALL_OLD'|'NONE'
)
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 simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide both values for both the partition key and the sort key.
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.
Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index.
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.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
dict
This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide .
(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 the expected attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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 ConditionCheckFailedException .
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 ConditionCheckFailedException .
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 provide 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 data types, 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 provided 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 data types, 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 provided 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 provided 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 provided 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 provided 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 provided 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 data types, including lists and maps.
Note
This operator tests for the existence of an attribute, not its data type. If the data type of attribute " a " is null, and you evaluate it using NOT_NULL , the result is a Boolean true . This result is because the attribute " a " exists; its data type is not relevant to the NOT_NULL comparison operator.
NULL : The attribute does not exist. NULL is supported for all data types, including lists and maps.
Note
This operator tests for the nonexistence of an attribute, not its data type. If the data type of attribute " a " is null, and you evaluate it using NULL , the result is a Boolean false . This is because the attribute " a " exists; its data type is not relevant to the NULL comparison operator.
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 in a list. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary. These attributes are compared against an existing attribute of an item. If any elements of the input are equal to 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 provided 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 a 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 information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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.
The values returned are strongly consistent.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
Note
The ReturnValues parameter is used by several DynamoDB operations; however, PutItem does not recognize any values other than NONE or ALL_OLD .
string
Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:
INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
NONE - No ConsumedCapacity details are included in the response.
string
Determines whether item collection metrics are returned. 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
This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide .
string
A condition that must be satisfied in order for a conditional PutItem operation to succeed.
An expression can contain any of the following:
Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size These function names are case-sensitive.
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: AND | OR | NOT
For more information on condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide .
dict
One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames :
To access an attribute whose name conflicts with a DynamoDB reserved word.
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 attribute name:
Percentile
The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide ). To work around this, you could specify the following for ExpressionAttributeNames :
{"#P":"Percentile"}
You could then use this substitution in an expression, as in this example:
#P = :val
Note
Tokens that begin with the : character are expression attribute values , which are placeholders for the actual value at runtime.
For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide .
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:
Available | Backordered | Discontinued
You would first need to specify ExpressionAttributeValues as follows:
{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }
You could then use these values in an expression, such as this:
ProductStatus IN (:avail, :back, :disc)
For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide .
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
string
An optional parameter that returns the item attributes for a PutItem operation that failed a condition check.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
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,
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'Table': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'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.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ConsumedCapacity (dict) --
The capacity units consumed by the PutItem 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 ReturnConsumedCapacity parameter was specified. 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed by the operation.
WriteCapacityUnits (float) --
The total number of write capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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 PutItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. 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 partition key value of the item collection. This is the same as the partition key value of the item itself.
SizeEstimateRangeGB - 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 partition key value of the item collection. This value is the same as the partition key value of the item.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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) --
{'ReturnValuesOnConditionCheckFailure': 'ALL_OLD | NONE'}
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 on an existing item (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.
See also: AWS API Documentation
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
}
},
ReturnValuesOnConditionCheckFailure='ALL_OLD'|'NONE'
)
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 simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
dict
This is a legacy parameter. Use UpdateExpression instead. For more information, see AttributeUpdates in the Amazon DynamoDB Developer Guide .
(string) --
(dict) --
For the UpdateItem operation, represents the attributes to be modified, the action to perform on each, and the new value for each.
Note
You cannot use UpdateItem to update any primary key attributes. Instead, you will need to delete the item, and then use PutItem to create a new item with new attributes.
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.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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.
Note
If you use ADD to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses 0 as the initial value. In addition, if you use ADD to update an existing item, and intend to increment or decrement an attribute value which does not yet exist, DynamoDB uses 0 as the initial value. For example, suppose that the item you want to update does not yet have an attribute named itemcount , but you decide to ADD the number 3 to this attribute anyway, even though it currently does not exist. DynamoDB will create the itemcount attribute, set its initial value to 0 , and finally add 3 to it. The result will be a new itemcount attribute in the item, with a value of 3 .
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 a new item with the supplied primary key and number (or set) for the attribute value. The only data types allowed are number, number set, string set or binary set.
dict
This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide .
(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 the expected attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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 ConditionCheckFailedException .
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 ConditionCheckFailedException .
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 provide 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 data types, 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 provided 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 data types, 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 provided 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 provided 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 provided 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 provided 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 provided 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 data types, including lists and maps.
Note
This operator tests for the existence of an attribute, not its data type. If the data type of attribute " a " is null, and you evaluate it using NOT_NULL , the result is a Boolean true . This result is because the attribute " a " exists; its data type is not relevant to the NOT_NULL comparison operator.
NULL : The attribute does not exist. NULL is supported for all data types, including lists and maps.
Note
This operator tests for the nonexistence of an attribute, not its data type. If the data type of attribute " a " is null, and you evaluate it using NULL , the result is a Boolean false . This is because the attribute " a " exists; its data type is not relevant to the NULL comparison operator.
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 in a list. AttributeValueList can contain one or more AttributeValue elements of type String, Number, or Binary. These attributes are compared against an existing attribute of an item. If any elements of the input are equal to 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 provided 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 a 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 information on specifying data types in JSON, see JSON Data Format in the Amazon DynamoDB Developer Guide .
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
string
This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide .
string
Use ReturnValues if you want to get the item attributes as they appear before or after they are successfully 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 - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.
UPDATED_OLD - Returns only the updated attributes, as they appeared before the UpdateItem operation.
ALL_NEW - Returns all of the attributes of the item, as they appear after the UpdateItem operation.
UPDATED_NEW - Returns only the updated attributes, as they appear after the UpdateItem operation.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
The values returned are strongly consistent.
string
Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:
INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
NONE - No ConsumedCapacity details are included in the response.
string
Determines whether item collection metrics are returned. 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 values 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 attributes 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. For example: SET myNum = myNum + :val 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.
Note
If you use ADD to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses 0 as the initial value. Similarly, if you use ADD for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses 0 as the initial value. For example, suppose that the item you want to update doesn't have an attribute named itemcount , but you decide to ADD the number 3 to this attribute anyway. DynamoDB will create the itemcount attribute, set its initial value to 0 , and finally add 3 to it. The result will be a new itemcount attribute in the item, with a value of 3 .
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 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
For more information on update expressions, see Modifying Items and Attributes in the Amazon DynamoDB Developer Guide .
string
A condition that must be satisfied in order for a conditional update to succeed.
An expression can contain any of the following:
Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size These function names are case-sensitive.
Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
Logical operators: AND | OR | NOT
For more information about condition expressions, see Specifying Conditions in the Amazon DynamoDB Developer Guide .
dict
One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames :
To access an attribute whose name conflicts with a DynamoDB reserved word.
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 attribute name:
Percentile
The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide .) To work around this, you could specify the following for ExpressionAttributeNames :
{"#P":"Percentile"}
You could then use this substitution in an expression, as in this example:
#P = :val
Note
Tokens that begin with the : character are expression attribute values , which are placeholders for the actual value at runtime.
For more information about expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide .
(string) --
(string) --
dict
One or more values that can be substituted in an expression.
Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:
Available | Backordered | Discontinued
You would first need to specify ExpressionAttributeValues as follows:
{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }
You could then use these values in an expression, such as this:
ProductStatus IN (:avail, :back, :disc)
For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide .
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
string
An optional parameter that returns the item attributes for an UpdateItem operation that failed a condition check.
There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.
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,
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'Table': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
},
'LocalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'CapacityUnits': 123.0
}
},
'GlobalSecondaryIndexes': {
'string': {
'ReadCapacityUnits': 123.0,
'WriteCapacityUnits': 123.0,
'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 appear before or after the UpdateItem operation, as determined by the ReturnValues parameter.
The Attributes map is only present if the update was successful and ReturnValues was specified as something other than NONE in the request. Each element represents one attribute.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
ConsumedCapacity (dict) --
The capacity units consumed by the UpdateItem 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 ReturnConsumedCapacity parameter was specified. 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed by the operation.
WriteCapacityUnits (float) --
The total number of write capacity units consumed by the operation.
Table (dict) --
The amount of throughput consumed on the table affected by the operation.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units consumed on a table or an index.
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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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.
ReadCapacityUnits (float) --
The total number of read capacity units consumed on a table or an index.
WriteCapacityUnits (float) --
The total number of write capacity units 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 UpdateItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. 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 partition key value of the item collection. This is the same as the partition key value of the item itself.
SizeEstimateRangeGB - 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 partition key value of the item collection. This value is the same as the partition key value of the item.
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
S (string) --
An attribute of type String. For example:
"S": "Hello"
N (string) --
An attribute of type Number. For example:
"N": "123.45"
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
B (bytes) --
An attribute of type Binary. For example:
"B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
SS (list) --
An attribute of type String Set. For example:
"SS": ["Giraffe", "Hippo" ,"Zebra"]
(string) --
NS (list) --
An attribute of type Number Set. For example:
"NS": ["42.2", "-19", "7.5", "3.14"]
Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
(string) --
BS (list) --
An attribute of type Binary Set. For example:
"BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
(bytes) --
M (dict) --
An attribute of type Map. For example:
"M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
(string) --
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
L (list) --
An attribute of type List. For example:
"L": [ {"S": "Cookies"} , {"S": "Coffee"}, {"N": "3.14159"}]
(dict) --
Represents the data for an attribute.
Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
For more information, see Data Types in the Amazon DynamoDB Developer Guide .
NULL (boolean) --
An attribute of type Null. For example:
"NULL": true
BOOL (boolean) --
An attribute of type Boolean. For example:
"BOOL": true
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) --