Re: Two questions in Oracle...

1. Done.
2. This may be viable workaround but not an exact solution to your request because a) You will not update statements that change 'abc' to 'abc'. b) You will not detect updates to or from nulls.

You may add a check for NULL because the comparison would always fail if one of :new.fielda, :old.fielda is null. If both were null it depends if you reckon that as an update or not.

Martin

david.archer_at_chase.com wrote:
>
> I see your first part has been answered. Let me have a stab at question
> 2.
>
> Try the following:
>
> IF Updating THEN
> IF :NEW.fieldA <> :OLD.fieldA THEN
> PRO1;
> END IF;
> PRO_ALL;
> ELSIF Inserting THEN
> ...
> ELSIF Deleting THEN
> ...
> END IF;
>
> Good Luck,
>
> David Archer
>
> In article <37C60A34.BA2A611B_at_comp.polyu.edu.hk>,
> Jimmy <c6635500_at_comp.polyu.edu.hk> wrote:
> > Hello all,
> > I have two questions: (in Oracle 7.3.3)
> >
> > 1) Why the following SQL statement returns 'aaa'?
> >
> > select 'aaa' from dual where 'LOW_D_LIMIT' like 'L_%';
> >
> > Is '_' means special character? 'LOW_D_LIMIT' not contains the
> > string like 'L_' and it should return 'no rows returned' I
> > think......... but it returns 'aaa'....
> >
> > 2) I want to develop a trigger like this:
> >
> > create or replace trigger testing
> > after update or insert or delete on aaa
> > begin
> > if updating then
> > if updating(fieldA) then
> > pro1;
> > end if;
> > pro_all;
> > elsif inserting then
> > ...
> > elsif deleting then
> > ...
> > end if;
> > end;
> > /
> >
> > If update column fieldA, then do pro1 and pro_all Other columns
> > updating do only pro_all.
> > However, errors in creating this trigger.... Is it possible to
> check
> > which column is updated in the updating part? I cannot do this:
> >
> > create or replace trigger testing
> > after update(fieldA) or insert or delete on aaa
> > ...
> >
> > since this trigger only fired if fieldA is updated.
> >
> > Thanks,
> > Jimmy
> >
> >
>
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Received on Sat Sep 04 1999 - 03:29:16 CDT