Skip to content

Put Item

dynamodb_put_item R Documentation

Creates a new item, or replaces an old item with a new item

Description

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.

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 put_item, see Working with Items in the Amazon DynamoDB Developer Guide.

Usage

dynamodb_put_item(TableName, Item, Expected, ReturnValues,
  ReturnConsumedCapacity, ReturnItemCollectionMetrics,
  ConditionalOperator, ConditionExpression, ExpressionAttributeNames,
  ExpressionAttributeValues, ReturnValuesOnConditionCheckFailure)

Arguments

TableName

[required] The name of the table to contain the item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

Item

[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.

Expected

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

ReturnValues

Use ReturnValues if you want to get the item attributes as they appeared before they were updated with the put_item request. For put_item, 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 put_item 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.

The ReturnValues parameter is used by several DynamoDB operations; however, put_item does not recognize any values other than NONE or ALL_OLD.

ReturnConsumedCapacity
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.

ConditionalOperator

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

ConditionExpression

A condition that must be satisfied in order for a conditional put_item 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.

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

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.

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.

ReturnValuesOnConditionCheckFailure

An optional parameter that returns the item attributes for a put_item 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.

Value

A list with the following syntax: 

list(
  Attributes = 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
    )
  ),
  ConsumedCapacity = list(
    TableName = "string",
    CapacityUnits = 123.0,
    ReadCapacityUnits = 123.0,
    WriteCapacityUnits = 123.0,
    Table = list(
      ReadCapacityUnits = 123.0,
      WriteCapacityUnits = 123.0,
      CapacityUnits = 123.0
    ),
    LocalSecondaryIndexes = list(
      list(
        ReadCapacityUnits = 123.0,
        WriteCapacityUnits = 123.0,
        CapacityUnits = 123.0
      )
    ),
    GlobalSecondaryIndexes = list(
      list(
        ReadCapacityUnits = 123.0,
        WriteCapacityUnits = 123.0,
        CapacityUnits = 123.0
      )
    )
  ),
  ItemCollectionMetrics = list(
    ItemCollectionKey = 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
      )
    ),
    SizeEstimateRangeGB = list(
      123.0
    )
  )
)

Request syntax

svc$put_item(
  TableName = "string",
  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
    )
  ),
  Expected = list(
    list(
      Value = 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
      ),
      Exists = TRUE|FALSE,
      ComparisonOperator = "EQ"|"NE"|"IN"|"LE"|"LT"|"GE"|"GT"|"BETWEEN"|"NOT_NULL"|"NULL"|"CONTAINS"|"NOT_CONTAINS"|"BEGINS_WITH",
      AttributeValueList = 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
        )
      )
    )
  ),
  ReturnValues = "NONE"|"ALL_OLD"|"UPDATED_OLD"|"ALL_NEW"|"UPDATED_NEW",
  ReturnConsumedCapacity = "INDEXES"|"TOTAL"|"NONE",
  ReturnItemCollectionMetrics = "SIZE"|"NONE",
  ConditionalOperator = "AND"|"OR",
  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"
)

Examples

## Not run: 
# This example adds a new item to the Music table.
svc$put_item(
  Item = list(
    AlbumTitle = list(
      S = "Somewhat Famous"
    ),
    Artist = list(
      S = "No One You Know"
    ),
    SongTitle = list(
      S = "Call Me Today"
    )
  ),
  ReturnConsumedCapacity = "TOTAL",
  TableName = "Music"
)

## End(Not run)