replace foreign key with on delete cascade with trigger

[Axr2]

Wooo..Sorry. I completely misunderstood your initial question. I thought you wanted to implement "delete cascade" instead of triggers..rather than the other way around!

I'm not much of a developer..but that seems like a bad idea. You're reinventing the wheel..and setting yourself for mutation problems.

The "select version_id from grp where grp_id = : old.grp_id" in the trigger is obviously causing the mutating error. Don't select it, rather find a way around it..can't you use the old version_id directly?

PS : Why are you even going this route?