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.
This topic provides general information about the PutItem
API.
For information on how to call the PutItem
API using the AWS SDK in specific languages, see the
following:
When you add an item, the primary key attribute(s) are the only required attributes. Attribute values cannot be
null. String and Binary type attributes must have lengths greater than zero. Set type attributes cannot be empty.
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 PutItem
, see Working with
Items in the Amazon DynamoDB Developer Guide.