BULK COLLECT in select query inside a function

Question

Hi All,
My query is :
SELECT col1,col2,col3 FROM table_a; --( consider this is a long running query with lot of joins)
Need to know how can i get the output of the above query from a function using BULK COLLECT.
and i tried this:
CREATE OR REPLACE TYPE tab_a_row
AS OBJECT (
col1 number(20),
col2 number(20),
col2 number(20)) ;
create or replace type tab_a_nt as table of tab_a_row;
create or replace function get_table_a
return sys_refcursor
is
tab_a_recs tab_a_nt;
rv sys_refcursor;
begin
SELECT tab_a_row(col1,col2,col3) BULK COLLECT INTO tab_a_recs FROM table_a;
open rv for select * from table(tab_a_recs);
return rv;
end;
Function created successfully. and i exec this from sql plus using
SQL> var rc refcursor;
SQL> exec :rc := get_table_a;
BEGIN :rc := get_table_a; END;
ERROR at line 1:
ORA-22905: cannot access rows from a non-nested table item
ORA-06512: at "GET_TABLE_A", line 12
ORA-06512: at line 1
Kindly share your ideas on how to use bulk collect and get set of outputs from a function.
Edited by: 887268 on Apr 18, 2013 3:10 AM

Answer 1

>
If i use refcursor , then the JAVA code needs to be changed accordinglyto get the refcursor output.
>
Well, of course. Java has to know what the sql projection is. How else will it know how many columns there are and their datatypes.
But that is true no matter what method you use.
>
But if i use a PLSQL COLLECTION TYPE (nested tables ) , then i can get output as ,
select * from table(function_name(input1,input2));
>
No - using the 'table' function mean you are calling a PIPELINED function.
This is a sample of a PIPELINED procedure.
-- type to match emp record
create or replace type emp_scalar_type as object
  (EMPNO NUMBER(4) ,
   ENAME VARCHAR2(10),
   JOB VARCHAR2(9),
   MGR NUMBER(4),
   HIREDATE DATE,
   SAL NUMBER(7, 2),
   COMM NUMBER(7, 2),
   DEPTNO NUMBER(2)
-- table of emp records
create or replace type emp_table_type as table of emp_scalar_type
-- pipelined function
create or replace function get_emp( p_deptno in number )
  return emp_table_type
  PIPELINED
  as
   TYPE EmpCurTyp IS REF CURSOR RETURN emp%ROWTYPE;
    emp_cv EmpCurTyp;
    l_rec  emp%rowtype;
  begin
    open emp_cv for select * from emp where deptno = p_deptno;
    loop
      fetch emp_cv into l_rec;
      exit when (emp_cv%notfound);
      pipe row( emp_scalar_type( l_rec.empno, LOWER(l_rec.ename),
          l_rec.job, l_rec.mgr, l_rec.hiredate, l_rec.sal, l_rec.comm, l_rec.deptno ) );
    end loop;
    return;
  end;
select * from table(get_emp(20))Or your function could return a collection like the example from this thread this morning.
Example of Collection as datatype of a function’s return value
CREATE OR REPLACE TYPE enamelist as VARRAY(20) of VARCHAR2(20)
/* Formatted on 4/18/2013 4:06:47 PM (QP5 v5.126.903.23003) */
CREATE OR REPLACE FUNCTION ename_fn
RETURN enamelist
AS
v_cursor_main enamelist := enamelist ();
BEGIN
SELECT ename
BULK COLLECT
INTO v_cursor_main
FROM emp;
RETURN v_cursor_main;
EXCEPTION
WHEN OTHERS
THEN
RETURN v_cursor_main;
END;
select * from table(ename_fn()) from dual;
COLUMN_VALUE
SMITH
ALLEN
WARD
JONES
MARTIN
BLAKE
CLARK
SCOTT
KING
TURNER
ADAMS
JAMES
FORD
MILLER