Re: [GENERAL] How to handle simultaneous FOR-IN UPDATE-RETURNING loops?

[Alexander Farber]

I have tried:

  FOR _gid, _loser, _winner IN
        UPDATE  words_games
        SET     finished = CURRENT_TIMESTAMP
        WHERE   finished IS NULL
        AND     played1 IS NOT NULL
        AND     played2 IS NOT NULL
        AND     (played1 < CURRENT_TIMESTAMP - INTERVAL '24 hours'
        OR       played2 < CURRENT_TIMESTAMP - INTERVAL '24 hours')
        RETURNING
                gid,
                CASE WHEN played1 < played2 THEN player1 ELSE player2 END,
                CASE WHEN played1 < played2 THEN player2 ELSE player1 END
        FOR UPDATE SKIP LOCKED
  LOOP
    ...
  END LOOP;

but this fails with:

    ERROR:  syntax error at or near "FOR"

I have also described my problem at SO:


https://stackoverflow.com/questions/45015368/how-to-handle-simultaneous-for-in-update-returning-loops

Thank you
Alex