PartiQL update statements for DynamoDB - Amazon DynamoDB
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PartiQL update statements for DynamoDB

Use the UPDATE statement to modify the value of one or more attributes within an item in an Amazon DynamoDB table.

Note

You can only update one item at a time; you cannot issue a single DynamoDB PartiQL statement that updates multiple items. For information on updating multiple items, see Performing transactions with PartiQL for DynamoDB or Running batch operations with PartiQL for DynamoDB.

Syntax

UPDATE table [SET | REMOVE] path [= data] […] WHERE condition [RETURNING returnvalues] <returnvalues> ::= [ALL OLD | MODIFIED OLD | ALL NEW | MODIFIED NEW] *

Parameters

table

(Required) The table containing the data to be modified.

path

(Required) An attribute name or document path to be created or modified.

data

(Required) An attribute value or the result of an operation.

The supported operations to use with SET:

  • LIST_APPEND: adds a value to a list type.

  • SET_ADD: adds a value to a number or string set.

  • SET_DELETE: removes a value from a number or string set.

condition

(Required) The selection criteria for the item to be modified. This condition must resolve to a single primary key value.

returnvalues

(Optional) Use returnvalues if you want to get the item attributes as they appear before or after they are updated. The valid values are:

  • ALL OLD *- Returns all of the attributes of the item, as they appeared before the update operation.

  • MODIFIED OLD *- Returns only the updated attributes, as they appeared before the update operation.

  • ALL NEW *- Returns all of the attributes of the item, as they appear after the update operation.

  • MODIFIED NEW *- Returns only the updated attributes, as they appear after the UpdateItem operation.

Return value

This statement does not return a value unless returnvalues parameter is specified.

Note

If the WHERE clause of the UPDATE statement does not evaluate to true for any item in the DynamoDB table, ConditionalCheckFailedException is returned.

Examples

Update an attribute value in an existing item. If the attribute does not exist, it is created.

The following query updates an item in the "Music" table by adding an attribute of type number (AwardsWon) and an attribute of type map (AwardDetail).

UPDATE "Music" SET AwardsWon=1 SET AwardDetail={'Grammys':[2020, 2018]} WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks'

You can add RETURNING ALL OLD * to return the attributes as they appeared before the Update operation.

UPDATE "Music" SET AwardsWon=1 SET AwardDetail={'Grammys':[2020, 2018]} WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks' RETURNING ALL OLD *

This returns the following:

{ "Items": [ { "Artist": { "S": "Acme Band" }, "SongTitle": { "S": "PartiQL Rocks" } } ] }

You can add RETURNING ALL NEW * to return the attributes as they appeared after the Update operation.

UPDATE "Music" SET AwardsWon=1 SET AwardDetail={'Grammys':[2020, 2018]} WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks' RETURNING ALL NEW *

This returns the following:

{ "Items": [ { "AwardDetail": { "M": { "Grammys": { "L": [ { "N": "2020" }, { "N": "2018" } ] } } }, "AwardsWon": { "N": "1" } } ] }

The following query updates an item in the "Music" table by appending to a list AwardDetail.Grammys.

UPDATE "Music" SET AwardDetail.Grammys =list_append(AwardDetail.Grammys,[2016]) WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks'

The following query updates an item in the "Music" table by removing from a list AwardDetail.Grammys.

UPDATE "Music" REMOVE AwardDetail.Grammys[2] WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks'

The following query updates an item in the "Music" table by adding BillBoard to the map AwardDetail.

UPDATE "Music" SET AwardDetail.BillBoard=[2020] WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks'

The following query updates an item in the "Music" table by adding the string set attribute BandMembers.

UPDATE "Music" SET BandMembers =<<'member1', 'member2'>> WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks'

The following query updates an item in the "Music" table by adding newbandmember to the string set BandMembers.

UPDATE "Music" SET BandMembers =set_add(BandMembers, <<'newbandmember'>>) WHERE Artist='Acme Band' AND SongTitle='PartiQL Rocks'