I have a table that has a bunch of columns, one of which is a ‘last_update_time’ column. Whenever I change the value of any of the other columns, I would like ‘last_update_time’ to automatically update to
I know that you would usually use triggers for this kind of thing, but as far as I am aware it is not possible to have a trigger for a table mutate that same table.
What is the best way of implementing the functionallity described above?
You can use a trigger before update of. You only need to specify the columns that might be updated in the clause before of
Take a look at this
SQL> create table testtrg ( c1 number, c2 date ) ; Table created. SQL> create or replace trigger mytrig before update of c1 on testtrg referencing new as new old as old for each row declare begin :new.c2 := sysdate; end; / 2 3 4 5 6 7 8 9 10 11 12 13 Trigger created. SQL> select * from testtrg; no rows selected SQL> insert into testtrg values ( 1 , sysdate - 360 ); 1 row created. SQL> commit; Commit complete. SQL> select * from testtrg ; C1 C2 ---------- --------- 1 28-JUL-19 SQL> update testtrg set c1=2 ; 1 row updated. SQL> commit ; Commit complete. SQL> select * from testtrg ; C1 C2 ---------- --------- 2 22-JUL-20 SQL>