oracle - Trigger creation on a table for inserting value in a column -

how create trigger insert value in column depending on combination of 3 other columns of same table of newly inserted row in table.

create or replace trigger execution_trigger   after insert on jobs   declare  v_a varchar2(100); v_b varchar2(100); v_c varchar2(120);  begin  select category, method,tech  v_a, v_b, v_c jobs  if  v_c = '10x' , v_b = '20x' , v_a = '30x'   update jobs  set execution = 1;  else   update jobs  set execution = 2;   end if ;   null; end 

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i not able execute this...

you need before insert trigger here:

create or replace trigger execution_trigger before insert on jobs   each row begin   if :new.category = '30x' , :new.method = '20x' , :new.tech = '10x'     :new.execution := 1;    else     :new.execution := 2;    end if; end; 

test:

create table jobs (category varchar2(10), method    varchar2(10),                    tech      varchar2(10), execution number(5));  insert jobs (category, method, tech) values ('30x', '20x', '10x'); insert jobs (category, method, tech) values ('abc', 'def', 'ghi');  select * jobs;  category   method     tech        execution ---------- ---------- ---------- ---------- 30x        20x        10x                 1  abc        def        ghi                 2