Two questions in Oracle...

From: Jimmy <c6635500_at_comp.polyu.edu.hk>
Date: Thu, 26 Aug 1999 20:49:29 -0700
Message-ID: <37C60AC9.5CB7A5B@comp.polyu.edu.hk>

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 Received on Thu Aug 26 1999 - 22:49:29 CDT