Amazon DynamoDB
API Reference

TransactWriteItems

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.

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  —   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  —   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  —   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  —   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.

Request Syntax

{ "ClientRequestToken": "string", "ReturnConsumedCapacity": "string", "ReturnItemCollectionMetrics": "string", "TransactItems": [ { "ConditionCheck": { "ConditionExpression": "string", "ExpressionAttributeNames": { "string" : "string" }, "ExpressionAttributeValues": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "Key": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "ReturnValuesOnConditionCheckFailure": "string", "TableName": "string" }, "Delete": { "ConditionExpression": "string", "ExpressionAttributeNames": { "string" : "string" }, "ExpressionAttributeValues": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "Key": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "ReturnValuesOnConditionCheckFailure": "string", "TableName": "string" }, "Put": { "ConditionExpression": "string", "ExpressionAttributeNames": { "string" : "string" }, "ExpressionAttributeValues": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "Item": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "ReturnValuesOnConditionCheckFailure": "string", "TableName": "string" }, "Update": { "ConditionExpression": "string", "ExpressionAttributeNames": { "string" : "string" }, "ExpressionAttributeValues": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "Key": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "ReturnValuesOnConditionCheckFailure": "string", "TableName": "string", "UpdateExpression": "string" } } ] }

Request Parameters

The request accepts the following data in JSON format.

Note

In the following list, the required parameters are described first.

TransactItems

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.

Type: Array of TransactWriteItem objects

Array Members: Minimum number of 1 item. Maximum number of 25 items.

Required: Yes

ClientRequestToken

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.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 36.

Required: No

ReturnConsumedCapacity

Determines the level of detail about provisioned 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.

Type: String

Valid Values: INDEXES | TOTAL | NONE

Required: No

ReturnItemCollectionMetrics

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.

Type: String

Valid Values: SIZE | NONE

Required: No

Response Syntax

{ "ConsumedCapacity": [ { "CapacityUnits": number, "GlobalSecondaryIndexes": { "string" : { "CapacityUnits": number, "ReadCapacityUnits": number, "WriteCapacityUnits": number } }, "LocalSecondaryIndexes": { "string" : { "CapacityUnits": number, "ReadCapacityUnits": number, "WriteCapacityUnits": number } }, "ReadCapacityUnits": number, "Table": { "CapacityUnits": number, "ReadCapacityUnits": number, "WriteCapacityUnits": number }, "TableName": "string", "WriteCapacityUnits": number } ], "ItemCollectionMetrics": { "string" : [ { "ItemCollectionKey": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "SizeEstimateRangeGB": [ number ] } ] } }

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

ConsumedCapacity

The capacity units consumed by the entire TransactWriteItems operation. The values of the list are ordered according to the ordering of the TransactItems request parameter.

Type: Array of ConsumedCapacity objects

ItemCollectionMetrics

A list of tables that were processed by TransactWriteItems and, for each table, information about any item collections that were affected by individual UpdateItem, PutItem, or DeleteItem operations.

Type: String to array of ItemCollectionMetrics objects map

Key Length Constraints: Minimum length of 3. Maximum length of 255.

Key Pattern: [a-zA-Z0-9_.-]+

Errors

For information about the errors that are common to all actions, see Common Errors.

IdempotentParameterMismatchException

DynamoDB rejected the request because you retried a request with a different payload but with an idempotent token that was already used.

HTTP Status Code: 400

InternalServerError

An error occurred on the server side.

HTTP Status Code: 500

ProvisionedThroughputExceededException

Your request rate is too high. The AWS SDKs for DynamoDB automatically retry requests that receive this exception. Your request is eventually successful, unless your retry queue is too large to finish. Reduce the frequency of requests and use exponential backoff. For more information, go to Error Retries and Exponential Backoff in the Amazon DynamoDB Developer Guide.

HTTP Status Code: 400

RequestLimitExceeded

Throughput exceeds the current throughput limit for your account. Please contact AWS Support at AWS Support to request a limit increase.

HTTP Status Code: 400

ResourceNotFoundException

The operation tried to access a nonexistent table or index. The resource might not be specified correctly, or its status might not be ACTIVE.

HTTP Status Code: 400

TransactionCanceledException

The entire transaction request was canceled.

DynamoDB cancels a TransactWriteItems request under the following circumstances:

  • A condition in one of the condition expressions is not met.

  • A table in the TransactWriteItems request is in a different account or region.

  • More than one action in the TransactWriteItems operation targets the same item.

  • There is insufficient provisioned capacity for the transaction to be completed.

  • An item size becomes too large (larger than 400 KB), or 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 MBs.

  • There is a user error, such as an invalid data format.

DynamoDB cancels a TransactGetItems request under the following circumstances:

  • There is an ongoing TransactGetItems operation that conflicts with a concurrent PutItem, UpdateItem, DeleteItem or TransactWriteItems request. In this case the TransactGetItems operation fails with a TransactionCanceledException.

  • A table in the TransactGetItems request is in a different account or region.

  • There is insufficient provisioned capacity for the transaction to be completed.

  • The aggregate size of the items in the transaction exceeds 4 MBs.

  • There is a user error, such as an invalid data format.

Note

If using Java, DynamoDB lists the cancellation reasons on the CancellationReasons property. This property is not set for other languages. Transaction cancellation reasons are ordered in the order of requested items, if an item has no error it will have NONE code and Null message.

Cancellation reason codes and possible error messages:

  • No Errors:

    • Code: NONE

    • Message: null

  • Conditional Check Failed:

    • Code: ConditionalCheckFailed

    • Message: The conditional request failed.

  • Item Collection Size Limit Exceeded:

    • Code: ItemCollectionSizeLimitExceeded

    • Message: Collection size exceeded.

  • Transaction Conflict:

    • Code: TransactionConflict

    • Message: Transaction is ongoing for the item.

  • Provisioned Throughput Exceeded:

    • Code: ProvisionedThroughputExceeded

    • Messages:

      • The level of configured provisioned throughput for the table was exceeded. Consider increasing your provisioning level with the UpdateTable API.

        Note

        This Message is received when provisioned throughput is exceeded is on a provisioned DynamoDB table.

      • The level of configured provisioned throughput for one or more global secondary indexes of the table was exceeded. Consider increasing your provisioning level for the under-provisioned global secondary indexes with the UpdateTable API.

        Note

        This message is returned when provisioned throughput is exceeded is on a provisioned GSI.

  • Throttling Error:

    • Code: ThrottlingError

    • Messages:

      • Throughput exceeds the current capacity of your table or index. DynamoDB is automatically scaling your table or index so please try again shortly. If exceptions persist, check if you have a hot key: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-partition-key-design.html.

        Note

        This message is returned when writes get throttled on an On-Demand table as DynamoDB is automatically scaling the table.

      • Throughput exceeds the current capacity for one or more global secondary indexes. DynamoDB is automatically scaling your index so please try again shortly.

        Note

        This message is returned when when writes get throttled on an On-Demand GSI as DynamoDB is automatically scaling the GSI.

  • Validation Error:

    • Code: ValidationError

    • Messages:

      • One or more parameter values were invalid.

      • The update expression attempted to update the secondary index key beyond allowed size limits.

      • The update expression attempted to update the secondary index key to unsupported type.

      • An operand in the update expression has an incorrect data type.

      • Item size to update has exceeded the maximum allowed size.

      • Number overflow. Attempting to store a number with magnitude larger than supported range.

      • Type mismatch for attribute to update.

      • Nesting Levels have exceeded supported limits.

      • The document path provided in the update expression is invalid for update.

      • The provided expression refers to an attribute that does not exist in the item.

HTTP Status Code: 400

TransactionInProgressException

The transaction with the given request token is already in progress.

HTTP Status Code: 400

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: