hi all. i'm new to postgresql and this is the first time that i'm posting a thread. i would like to know the diff between opaque and trigger when creating a function that returns a value. this is bcoz i saw some sample that returns opaque and some returns trigger. so i would like to know the diff.

and is it true that postgresql functions cannot return values if it is implemented with triggers? this is bcoz i keep getting an error message saying that the function .... doesn't exist. becoz of this error, i can't created my trigger. please advice. thanks in advance.