INSTEAD OF trigger to update on a view

The following CREATE TRIGGER statement creates manager_info_update, an INSTEAD OF trigger that is designed to update rows within the dept and emp tables through the manager_info view.

CREATE TRIGGER manager_info_update
   INSTEAD OF UPDATE ON manager_info 
      REFERENCING NEW AS n 
   FOR EACH ROW 
      (EXECUTE PROCEDURE updtab (n.empno, n.empname, n.deptno,));

CREATE PROCEDURE updtab (eno INT, ename CHAR(20), dno INT,)
   DEFINE deptcode INT;
   UPDATE dept SET manager_num = eno where deptno = dno;
   SELECT deptno INTO deptcode FROM emp WHERE empno = eno; 
   IF dno !=deptcode THEN
      UPDATE emp SET deptno = dno WHERE empno = eno;
   END IF;
   END PROCEDURE;

After the tables, view, trigger, and SPL routine have been created, the database server treats the following UPDATE statement as a triggering event:

UPDATE manager_info
   SET empno = 3666, empname = “Steve”
   WHERE deptno = 01;