Oracle: excluding updates of one column for firing a trigger

Question

In oracle I can specify the columns, which should induce a firing of a trigger:

create or replace trigger my_trigger
before update of col1, col2, col3 on my_         


        

Answer 1

You could do something like this:

create or replace trigger my_trigger
before update on my_table
for each row
declare
   n_cols integer := 0;
begin
   for r in (select column_name from all_tab_columns
             where table_name = 'MY_TABLE'
             and owner = 'MY_SCHEMA')
   loop
      if updating(r.column_name) then
         n_cols := n_cols + 1;
         exit when n_cols > 1;
      end if;
   end loop;
   if n_cols > 1 then
      do_something;
   end if;
end;

Probably not terribly efficient though!