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To: pgsql-sql@postgresql.org
Subject: UPDATE table SET col = (SELECT ...)
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From: Eric Marsden <emarsden@mail.dotcom.fr>
Date: 30 Dec 1998 18:01:28 +0100
Message-ID: <wzi4sqdzhqv.fsf@mail.dotcom.fr>
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Hello,

If I understand the SQL references I have read, UPDATEs are allowed to
pull data from SELECT statements, something like

  UPDATE table SET col1 = (SELECT val1 FROM table WHERE id = 34),
               SET col2 = (SELECT val2 FROM table WHERE id = 34)
         WHERE id = 35;

However, the PostgreSQL parser chokes on the 'SELECT'. The
documentation says

  UPDATE table SET column = expression [, ...]
      [ FROM fromlist ]
      [ WHERE condition ]         

  expression = A valid expression or value to assign to column.


I don't know exactly how to interpret `valid expression'.
      
-- 
Eric Marsden
emarsden @ mail.dotcom.fr
It's elephants all the way down