Re: MySQL UPDATE query

[Chris Stubben]

I copied this from the docs... You can't use maps in your subquery if its being updated.

Chris

--

Incorrectly used table in subquery:

Error 1093 (ER_UPDATE_TABLE_USED)
SQLSTATE = HY000
Message = "You can't specify target table 'x'
for update in FROM clause"

This error occurs in cases like this:

UPDATE t1 SET column2 = (SELECT MAX(column1) FROM t1);

It's okay to use a subquery for assignment within an UPDATE statement, since subqueries are legal in UPDATE and DELETE statements as well as in SELECT statements. However, you cannot use the same table, in this case table t1, for both the subquery's FROM clause and the update target.