TransactWriteItems
is a synchronous write operation that groups up to
25 action requests. These actions can target items in different tables,
but not in different AWS accounts or Regions, and no two actions can
target the same item. For example, you cannot both ConditionCheck
and
Update
the same item. The aggregate size of the items in the
transaction cannot exceed 4 MB.
dynamodb_transact_write_items(TransactItems, ReturnConsumedCapacity,
ReturnItemCollectionMetrics, ClientRequestToken)
[required] An ordered array of up to 25 TransactWriteItem
objects, each of which
contains a ConditionCheck
, Put
, Update
, or Delete
object. These
can operate on items in different tables, but the tables must reside in
the same AWS account and Region, and no two of them can operate on the
same item.
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 and are returned in the
response. If set to NONE
(the default), no statistics are returned.
Providing a ClientRequestToken
makes the call to TransactWriteItems
idempotent, meaning that multiple identical calls have the same effect
as one single call.
Although multiple identical calls using the same client request token
produce the same result on the server (no side effects), the responses
to the calls might not be the same. If the ReturnConsumedCapacity>
parameter is set, then the initial TransactWriteItems
call returns the
amount of write capacity units consumed in making the changes.
Subsequent TransactWriteItems
calls with the same client token return
the number of read capacity units consumed in reading the item.
A client request token is valid for 10 minutes after the first request that uses it is completed. After 10 minutes, any request with the same client token is treated as a new request. Do not resubmit the same request with the same client token for more than 10 minutes, or the result might not be idempotent.
If you submit a request with the same client token but a change in other
parameters within the 10-minute idempotency window, DynamoDB returns an
IdempotentParameterMismatch
exception.
svc$transact_write_items( TransactItems = list( list( ConditionCheck = list( Key = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), TableName = "string", ConditionExpression = "string", ExpressionAttributeNames = list( "string" ), ExpressionAttributeValues = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), ReturnValuesOnConditionCheckFailure = "ALL_OLD"|"NONE" ), Put = list( Item = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), TableName = "string", ConditionExpression = "string", ExpressionAttributeNames = list( "string" ), ExpressionAttributeValues = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), ReturnValuesOnConditionCheckFailure = "ALL_OLD"|"NONE" ), Delete = list( Key = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), TableName = "string", ConditionExpression = "string", ExpressionAttributeNames = list( "string" ), ExpressionAttributeValues = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), ReturnValuesOnConditionCheckFailure = "ALL_OLD"|"NONE" ), Update = list( Key = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), UpdateExpression = "string", TableName = "string", ConditionExpression = "string", ExpressionAttributeNames = list( "string" ), ExpressionAttributeValues = list( list( S = "string", N = "string", B = raw, SS = list( "string" ), NS = list( "string" ), BS = list( raw ), M = list( list() ), L = list( list() ), NULL = TRUE|FALSE, BOOL = TRUE|FALSE ) ), ReturnValuesOnConditionCheckFailure = "ALL_OLD"|"NONE" ) ) ), ReturnConsumedCapacity = "INDEXES"|"TOTAL"|"NONE", ReturnItemCollectionMetrics = "SIZE"|"NONE", ClientRequestToken = "string" )
All AWS Regions and AWS GovCloud (US) support up to 25 items per transaction with up to 4 MB of data, except the following AWS Regions:
China (Beijing)
China (Ningxia)
The China (Beijing) and China (Ningxia) Regions support up to 10 items per transaction with up to 4 MB of data.
The actions are completed atomically so that either all of them succeed, or all of them fail. They are defined by the following objects:
Put
<U+00C2><U+00A0>--- <U+00C2><U+00A0> Initiates a PutItem
operation to write a new item.
This structure specifies the primary key of the item to be written,
the name of the table to write it in, an optional condition
expression that must be satisfied for the write to succeed, a list
of the item's attributes, and a field indicating whether to
retrieve the item's attributes if the condition is not met.
Update
<U+00C2><U+00A0>--- <U+00C2><U+00A0> Initiates an UpdateItem
operation to update an
existing item. This structure specifies the primary key of the item
to be updated, the name of the table where it resides, an optional
condition expression that must be satisfied for the update to
succeed, an expression that defines one or more attributes to be
updated, and a field indicating whether to retrieve the item's
attributes if the condition is not met.
Delete
<U+00C2><U+00A0>--- <U+00C2><U+00A0> Initiates a DeleteItem
operation to delete an
existing item. This structure specifies the primary key of the item
to be deleted, the name of the table where it resides, an optional
condition expression that must be satisfied for the deletion to
succeed, and a field indicating whether to retrieve the item's
attributes if the condition is not met.
ConditionCheck
<U+00C2><U+00A0>--- <U+00C2><U+00A0> Applies a condition to an item that is not
being modified by the transaction. This structure specifies the
primary key of the item to be checked, the name of the table where
it resides, a condition expression that must be satisfied for the
transaction to succeed, and a field indicating whether to retrieve
the item's attributes if the condition is not met.
DynamoDB rejects the entire TransactWriteItems
request if any of the
following is true:
A condition in one of the condition expressions is not met.
An ongoing operation is in the process of updating the same item.
There is insufficient provisioned capacity for the transaction to be completed.
An item size becomes too large (bigger than 400 KB), a local secondary index (LSI) becomes too large, or a similar validation error occurs because of changes made by the transaction.
The aggregate size of the items in the transaction exceeds 4 MB.
There is a user error, such as an invalid data format.