NICE!!! Worked beautifully! I figured NULL's were not evaluating as a value, but I didn't have the correct operators:
these constructs effectively act as though null were a normal data value, > rather than “unknown”. I guess I wasn't reading the right part of the manuals! LOL! Thanks so much! Greg Fischer www.1stbyte.com On Tue, Mar 2, 2010 at 8:07 PM, Craig Ringer <cr...@postnewspapers.com.au>wrote: > Greg Fischer wrote: > > Hello all! > > I do my best to read and google my way around issues, but I seem to be > > missing something. Probably simple too. > > > > So I have a trigger function, in which I'd like to check if a particular > > column has changed. It works great, unless either the OLD or NEW values > > are NULL. The purpose is to create a audit/log of the record. I prefer > > to only test for certain columns, not the whole table. > > > > > > CREATE OR REPLACE FUNCTION tr_employees_bu() > > RETURNS trigger AS > > $BODY$ > > begin > > if (new.trainingdate <> old.trainingdate) then > > Instead, try the test: > > new.trainingdate IS DISTINCT FROM old.trainingdate > > See the manual for 'IS DISTINCT FROM'. > > -- > Craig Ringer >
