Daniel,
> IF (SELECT credit FROM users WHERE name = 'mary') < 0 THEN
> ROLLBACK;
> END IF
> COMMIT;
>
> i always get the error
> ERROR: syntax error at or near "IF"
>
> Where am i mistaken?
SELECT returns in essence a record or setof records.
DECLARE _credit int;
...
SELECT credit FROM users WHERE name = 'mary' INTO _credit;
IF _credit < 0 THEN
ROLLBACK;
END IF;
If there is a chance that the select returns more than one record you
can do something similar to:
DECLARE rec record;
...
FOR rec IN (SELECT credit FROM users WHERE name = 'mary'
LOOP
IF rec.credit < 0 THEN
...
ELSE
...
END IF;
END LOOP;
HTH,
Johan Nel
Pretoria, South Africa.