ORA-04091: table [blah] is mutating, trigger/function may not see it
I think I disagree with your description of what the trigger is trying to do. It looks to me like it is meant to enforce this business rule: For a given value of t1_appnt_event, only one row can have a non-NULL value of t1_prnt_t1_pk at a time. (It doesn’t matter if they have the same … Read more