UPDATE¶
Synopsis¶
UPDATE tablename
update_expression
[ KEYS IN primary_keys ]
[ WHERE expression ]
[ USING index ]
[ RETURNS (NONE | ( ALL | UPDATED) (NEW | OLD)) ]
[ THROTTLE throughput ]
Examples¶
UPDATE foobars SET foo = 'a';
UPDATE foobars SET foo = 'a', bar = bar + 4 WHERE id = 1 AND foo = 'b';
UPDATE foobars SET foo = if_not_exists(foo, 'a') RETURNS ALL NEW;
UPDATE foobars SET foo = list_append(foo, 'a') WHERE size(foo) < 3;
UPDATE foobars ADD foo 1, bar 4;
UPDATE foobars ADD fooset (1, 2);
UPDATE foobars REMOVE old_attribute;
UPDATE foobars DELETE fooset (1, 2);
Description¶
Update items in a table
Parameters¶
- tablename
- The name of the table
- RETURNS
- Return the items that were operated on. Default is RETURNS NONE. See the Amazon docs for UpdateItem for more detail.
- THROTTLE
- Limit the amount of throughput this query can consume. This is a pair of
values for
(read_throughput, write_throughput)
. You can use a flat number or a percentage (e.g.20
or50%
). Using*
means no limit (typically useless unless you have set a default throttle in the Options).
Update expression¶
All update syntax is pulled directly from the AWS docs:
http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html
In general, you may use any syntax mentioned in the docs, but you don’t need to
worry about reserved words or passing in data as variables like :var1
. DQL
will handle that for you.