A different RETURN clause in FUNCTION

Question

I am using Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production.
Hi Techie's,
I am having a table called DEV and trying to fetch all the records from a column called no from the same table. I know that i can do with the help of SYS_REFCURSOR. But I just tried to do something different here. When i compiled the function, it got created. But when i tried to execute, it throws some error.
I dont know what happens here between compilation and execution. Can someone give me some ideas? can we make this function to work? Correct me if i am understanding wrong.
CREATE OR REPLACE FUNCTION s_fn
RETURN dev%ROWTYPE
IS
   l_d   dev%ROWTYPE;
BEGIN
   SELECT * INTO l_d  FROM   dev;
   RETURN l_d;
END;
SELECT s_fn FROM DUALThanks
Ram

Answer 1

Your function is only expecting a single row to be returned from the SELECT statement, so if there's more than one row you'll get an error.
You need a pipeline function with a loop to achieve what you want. e.g.
SQL> CREATE OR REPLACE TYPE num_descript AS OBJECT(num number, descript varchar2(30))
  2  /
Type created.
SQL>
SQL> CREATE OR REPLACE TYPE tbl_num_descript AS TABLE OF num_descript
  2  /
Type created.
SQL>
SQL>
SQL> CREATE OR REPLACE PACKAGE reftest AS
  2    FUNCTION pipedata(p_choice number) RETURN tbl_num_descript PIPELINED;
  3  END;
  4  /
Package created.
SQL>
SQL> CREATE OR REPLACE PACKAGE BODY reftest AS
  2    FUNCTION pipedata(p_choice number) RETURN tbl_num_descript PIPELINED IS
  3      v_obj num_descript := num_descript(NULL,NULL);
  4      v_rc  sys_refcursor;
  5    BEGIN
  6      IF p_choice = 1 THEN
  7        OPEN v_rc FOR SELECT empno as num, ename as descript FROM emp;
  8      ELSIF p_choice = 2 THEN
  9        OPEN v_rc FOR SELECT deptno as num, dname as descript FROM dept;
10      END IF;
11      LOOP
12        FETCH v_rc INTO v_obj.num, v_obj.descript;
13        EXIT WHEN v_rc%NOTFOUND;
14        PIPE ROW(v_obj);
15      END LOOP;
16      CLOSE v_rc;
17      RETURN;
18    END;
19  END;
20  /
Package body created.
SQL> select * from table(reftest.pipedata(1));
       NUM DESCRIPT
      7369 SMITH
      7499 ALLEN
      7521 WARD
      7566 JONES
      7654 MARTIN
      7698 BLAKE
      7782 CLARK
      7788 SCOTT
      7839 KING
      7844 TURNER
      7876 ADAMS
      7900 JAMES
      7902 FORD
      7934 MILLER
14 rows selected.
SQL> select * from table(reftest.pipedata(2));
       NUM DESCRIPT
        10 ACCOUNTING
        20 RESEARCH
        30 SALES
        40 OPERATIONS
SQL>