How to use User defined Function in Update statement

Question

Hi All,
I have written below update statement to update column based on value return by function. but it is not working. Could any one help me on this. This function will return only one value for each project.
thanks in advance.
UPDATE dg2.OD_PROJ_LOOKUP_TEMP o
SET Months_In_Stage_Cnt = select Months_In_Stage_Cnt_ret(o.project_id) from dual;
thanks
deb

Answer 1

hi,
CREATE FUNCTION fn_emp_ename (p_empno IN emp.empno%TYPE)
   RETURN VARCHAR2
IS
   v_ename   emp.ename%TYPE;
BEGIN
   SELECT ename
     INTO v_ename
     FROM emp
    WHERE empno = p_empno;
   RETURN v_ename;
EXCEPTION
   WHEN NO_DATA_FOUND
   THEN
      RETURN NULL;
   WHEN OTHERS
   THEN
      RETURN NULL;
END fn_emp_ename;
SQL>
SQL> select * from emp;
     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
      7782 CLARK      MANAGER         7839 09-JUN-81       2450                    10
      7788 SCOTT      ANALYST         7566 19-APR-87       3000                    20
      7839 KING       PRESIDENT            17-NOV-81       5000                    10
      7844 TURNER     SALESMAN        7698 08-SEP-81       1500          0         30
      7876 ADAMS      CLERK           7788 23-MAY-87       1100                    20
      7900 JAMES      CLERK           7698 03-DEC-81        950                    30
      7902 FORD       ANALYST         7566 03-DEC-81       3000                    20
      7934 MILLER     CLERK           7782 23-JAN-82       1300                    10
14 rows selected.
SQL>  select fn_emp_ename (empno) as  emp_name from emp;
EMP_NAME
SMITH
ALLEN
WARD
JONES
MARTIN
BLAKE
CLARK
SCOTT
KING
TURNER
ADAMS
JAMES
FORD
MILLER
14 rows selected.
SQL> update emp
  2  set ename= fn_emp_ename (7936)
  3  where empno=7934;
1 row updated.
SQL> commit;
Commit complete.
SQL>  select * from emp where empno=7934;
     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTN
      7934            CLERK           7782 23-JAN-82       1300                    1
SQL> i hope this helps .........
Thanks,
P Prakash
Edited by: prakash on Nov 17, 2011 11:52 PM