Re: How to notice column changes in trigger

Andreas,

> 1) update test set a=0 -> trigger does its work
> 2) update test set a=0, b=1, c=2 -> trigger does nothing
> 3) update test set a=0, b=b, c=c -> trigger does nothing, but content of
> a and b dont change either although touched

> IF OLD.b=NEW.b will not work, case 3) will falsely execute the trigger
> code.

I still don't get why you'd want to do this.   Can you provide are real-world 
example where there is a difference between setting B=B and not updating B?

-- 
Josh Berkus
Aglio Database Solutions
San Francisco