Trigger on either of tables

Question

Hi I have a requirement like this,
desc emp
emp_id, emp_name,
desc emp_details
emp_id, emp_skills
desc emp_log
emp_id statusNow I want to write a trigger which satisfies following criteria
in emp am inserting below data
emp_id  emp_name
1           Sun
3           Gunin emp_skiills am inserting below data
emp_id emp_skills
2          SQL
3          PL/SQLnow with trigger I want data in emp_log table as below
emp_id    status
1             0
2             0
3             0i.e., if either of emp and emp_skills got inserted(in this case 1 and 2) then it should have log in emp_log table and when it is inserting in both then also it should have a single entry
Hope am clear,
Thanks in advance

Answer 1

Check below code:
SQL> create table emp (empid number,ename varchar2(10));
Table created.
SQL> create table emp_skill (empid number,emp_skills varchar2(10));
Table created.
SQL> ed
Wrote file afiedt.buf
  1  create or replace trigger my_trig1 AFTER INSERT ON emp_skill
  2  for each row
  3  declare
  4  v_cnt NUMBER := 0;
  5  begin
  6  SELECT COUNT(*) into v_cnt FROM emp_log WHERE empid = :new.empid;
  7  IF (v_cnt = 0) THEN
  8  insert into emp_log values(:new.empid,0);
  9  END IF;
10* END;
SQL> /
Trigger created.
SQL> ed
Wrote file afiedt.buf
  1  create or replace trigger my_trig AFTER INSERT ON emp
  2  for each row
  3  declare
  4  v_cnt NUMBER := 0;
  5  begin
  6  SELECT COUNT(*) into v_cnt FROM emp_log WHERE empid = :new.empid;
  8  IF (v_cnt = 0) THEN
  9  insert into emp_log values(:new.empid,0);
10  END IF;
11* END;
SQL> /
Trigger created.
SQL> select * from emp;
         1 ABCD
SQL> select * from emp_skill;
         1 PLSQL
SQL> select * from emp_log;
         1          0
SQL> insert into emp values(2,'DCS');
1 row created.
SQL> commit;
Commit complete.
SQL> select * from emp_log;
         1          0
         2          0
SQL> insert into emp_skill values(2,'SQL');
1 row created.
SQL> COMMIT;
Commit complete.
SQL> SELECT * from emp_log;
         1          0
         2          0
SQL> Edited by: AP on Jul 27, 2010 12:45 AM