Request Syntax Request Parameters Response Syntax Response Elements Errors Examples See Also

DeleteItem

Deletes a single item in a table by primary key. You can perform a conditional delete operation that deletes the item if it exists, or if it has an expected attribute value.

In addition to deleting an item, you can also return the item's attribute values in the same operation, using the ReturnValues parameter.

Unless you specify conditions, the DeleteItem is an idempotent operation; running it multiple times on the same item or attribute does not result in an error response.

Conditional deletes are useful for deleting items only if specific conditions are met. If those conditions are met, DynamoDB performs the delete. Otherwise, the item is not deleted.

Request Syntax


{
   "ConditionalOperator": "string",
   "ConditionExpression": "string",
   "Expected": { 
      "string" : { 
         "AttributeValueList": [ 
            { 
               "B": blob,
               "BOOL": boolean,
               "BS": [ blob ],
               "L": [ 
                  "AttributeValue"
               ],
               "M": { 
                  "string" : "AttributeValue"
               },
               "N": "string",
               "NS": [ "string" ],
               "NULL": boolean,
               "S": "string",
               "SS": [ "string" ]
            }
         ],
         "ComparisonOperator": "string",
         "Exists": boolean,
         "Value": { 
            "B": blob,
            "BOOL": boolean,
            "BS": [ blob ],
            "L": [ 
               "AttributeValue"
            ],
            "M": { 
               "string" : "AttributeValue"
            },
            "N": "string",
            "NS": [ "string" ],
            "NULL": boolean,
            "S": "string",
            "SS": [ "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" ]
      }
   },
   "ReturnConsumedCapacity": "string",
   "ReturnItemCollectionMetrics": "string",
   "ReturnValues": "string",
   "ReturnValuesOnConditionCheckFailure": "string",
   "TableName": "string"
}

Request Parameters

The request accepts the following data in JSON format.

Note

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

Key

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.

Type: String to AttributeValue object map

Key Length Constraints: Maximum length of 65535.

Required: Yes

TableName

The name of the table from which to delete the item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1024.

Required: Yes

ConditionalOperator

This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

Type: String

Valid Values: AND | OR

Required: No

ConditionExpression

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.

Type: String

Required: No

Expected

This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

Type: String to ExpectedAttributeValue object map

Key Length Constraints: Maximum length of 65535.

Required: No

ExpressionAttributeNames

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.

Type: String to string map

Value Length Constraints: Maximum length of 65535.

Required: No

ExpressionAttributeValues

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.

Type: String to AttributeValue object map

Required: No

ReturnConsumedCapacity

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.

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 are returned in the response. If set to NONE (the default), no statistics are returned.

Type: String

Valid Values: SIZE | NONE

Required: No

ReturnValues

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.

Type: String

Valid Values: NONE | ALL_OLD | UPDATED_OLD | ALL_NEW | UPDATED_NEW

Required: No

ReturnValuesOnConditionCheckFailure

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.

Type: String

Valid Values: ALL_OLD | NONE

Required: No

Response Syntax


{
   "Attributes": { 
      "string" : { 
         "B": blob,
         "BOOL": boolean,
         "BS": [ blob ],
         "L": [ 
            "AttributeValue"
         ],
         "M": { 
            "string" : "AttributeValue"
         },
         "N": "string",
         "NS": [ "string" ],
         "NULL": boolean,
         "S": "string",
         "SS": [ "string" ]
      }
   },
   "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",
      "VectorIndexes": { 
         "string" : { 
            "VectorSearchRequestBytes": number,
            "VectorWriteRequestBytes": number
         }
      },
      "WriteCapacityUnits": number
   },
   "ItemCollectionMetrics": { 
      "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.

Attributes

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.

Type: String to AttributeValue object map

Key Length Constraints: Maximum length of 65535.

ConsumedCapacity