put_item - Boto3 1.34.87 documentation

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) –

Expected (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 *(valid DynamoDB type) – *- The value of the attribute. The valid value types are listed in the DynamoDB Reference Guide.

    • 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.

      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 .

      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.

ReturnValues (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.

ReturnConsumedCapacity (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.

ReturnItemCollectionMetrics (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.

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

ConditionExpression (condition from boto3.dynamodb.conditions.Attr method) – The condition(s) an attribute(s) must meet. Valid conditions are listed in the DynamoDB Reference Guide.

ExpressionAttributeNames (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:

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) –

ExpressionAttributeValues (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) –

ReturnValuesOnConditionCheckFailure (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.