How to Use FOR UPDATE Clause

 

 

 

EMPNO	ENAME	JOB	MGR	HIREDATE	SAL	COMM	DEPTNO
7369	SMITH	CLERK	7902	17-Dec-80	800		20
7499	ALLEN	SALESMAN	7698	20-Feb-81	1600	300	30
7521	WARD	SALESMAN	7698	22-Feb-81	1250	500	30
7566	JONES	MANAGER	7839	02-Apr-81	2975		20
7654	MARTIN	SALESMAN	7698	28-Sep-81	1250	1400	30
7698	BLAKE	MANAGER	7839	01-May-81	2850		30
7788	SCOTT	ANALYST	7566	09-Dec-82	3000		20
7844	TURNER	SALESMAN	7698	08-Sep-81	1500	0	30
7876	ADAMS	CLERK	7788	12-Jan-83	1100		20
7900	JAMES	CLERK	7698	03-Dec-81	950		30
7902	FORD	ANALYST	7566	03-Dec-81	3000		20
7782	CLARK	MANAGER	7839	09-Jun-81	2450		10
7839	KING	PRESIDENT		17-Nov-81	5000		10
7934	MILLER	CLERK	7782	23-Jan-82	1300		10
9001	Manoj	CLERK		08-Nov-20	1000	450	40

 

 

--************************************   FOR UPDATE ***********************************-------

 

DECLARE

 

CURSOR  C1  IS

 

select * from XX_EMP

WHERE DEPTNO = 10

FOR UPDATE;

 

   

BEGIN

 

    FOR I IN C1 LOOP

        dbms_lock.sleep(10);   

        dbms_output.put_line ('Employee : '||I.ENAME ||' : Old  Salary is : '||I.SAL);

        UPDATE XX_EMP SET SAL = 15000

        WHERE EMPNO = I.EMPNO;

        dbms_output.put_line ('---*************************************   : '||I.ENAME ||' : Salary Updated OR Not 0/1 : '||SQL%ROWCOUNT);

 

    END LOOP;

 

 

 

END;

 

--=====================

DELETE from XX_EMP WHERE DEPTNO = 10;