CODEWITHSUNDEEP
amazon-dynamodbboto3
Constantin
Constantin

Reputation: 915

DynamoDB: Is it possible to retrieve the existent item when using attribute_not_exists?

I am using put_item along with ConditionExpression='attribute_not_exists(#primary_key)' to avoid duplicates for some dataset inserts.

Is it possible to allow put_item to return the duplicate item without having to perform any other client API call?

Upvotes: 0

Views: 152

Answers (1)

Seth Geoghegan
Seth Geoghegan

Reputation: 5747

According to the put_item docs

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.

I'm not sure how this behavior works when using attribute_not_exists, but perhaps it can give you a starting point?

Upvotes: 1

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