2012/10/29 Tom Lane <t...@sss.pgh.pa.us>: > Hannu Krosing <ha...@2ndquadrant.com> writes: >> Would just converting UNDEFINED to NULL be a very bad idea ? > > Yeah, it would, at least for the normal case where an undefined record > variable has no well-defined type either. Saying that it's NULL doesn't > provide an answer to what type it has. > > In the case of OLD/NEW we do know that they ought to have the rowtype of > the underlying table, so it's conceivable that we could pretend they are > nulls of that type. But then you get into the question of whether a > NULL record is distinguishable from (NULL, NULL, ...) --- which would be > a perfectly legal real value of these records. Note that the SQL > standard is pretty firmly on the side that says they are not > distinguishable. I don't agree with that personally, but I don't think > it'd be a good idea to make a fundamental plpgsql feature depend on > being able to distinguish these states. > > TBH, I think your request is ill-considered and should be rejected. > There is nothing whatsoever wrong with testing TG_OP to see what sort of > trigger you're in.
+1 we can define two vars TG_NEW_IS_VALID and TG_OLD_IS_VALID. and then you can write test IF TG_NEW_IS_VALID THEN -- do some with NEW ELSE -- ... END IF; Regards Pavel > > regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
