Is it possible, and how, to do a Oracle trigger "to see" some default value in column even if it´s not inserted yet? Mean, if :old is for update and :new is for insert and in this case I need to "cheat" trigger to believe something was inserted (:new) though I just want to update (:old) record.
Oracle version is so new, that even exotic ideas are welcome. Also it can be a combination of different mechanism if it's required to achieve this.
Not so exotic; user_tab_columns is what you might be using.
SQL> create table car
2 (name varchar2(20),
3 color varchar2(10) default 'RED');
Table created.
SQL> select data_default
2 from user_tab_columns
3 where table_name = 'CAR'
4 and column_name = 'COLOR';
DATA_DEFAULT
--------------------------------------------------------
'RED'
SQL> create or replace trigger trg_biu_car
2 before insert or update on car
3 for each row
4 declare
5 l_def_color car.color%type;
6 begin
7 select data_default
8 into l_def_color
9 from user_tab_columns
10 where table_name = 'CAR'
11 and column_name = 'COLOR';
12
13 -- your code now goes here
14 end;
15 /
Trigger created.
SQL>
