Can an SQL procedure return a table?

Jaqualembo picture Jaqualembo · Dec 2, 2012 · Viewed 34.4k times · Source

Can an Oracle SQL procedure return a table? I'm currently using a dbms_output to print out the outputs of two cursors which are in a loop, although this would look nicer if it was returning two columns instead. Would that be possible within a procedure?

Answer

APC picture APC · Dec 2, 2012

A PL/SQL function can return a nested table. Provided we declare the nested table as a SQL type we can use it as the source of a query, using the the TABLE() function.

Here is a type, and a nested table built from it:

SQL> create or replace type emp_dets as object (
  2  empno number,
  3  ename varchar2(30),
  4  job varchar2(20));
  5  /

Type created.

SQL> create or replace type emp_dets_nt as table of emp_dets;
  2  /

Type created.

SQL> 

Here is a function which returns that nested table ...

create or replace function get_emp_dets (p_dno in emp.deptno%type)
    return emp_dets_nt
is
    return_value emp_dets_nt;
begin
    select emp_dets(empno, ename, job)
    bulk collect into return_value
    from emp
    where deptno = p_dno;
    return return_value;
end;
/

... and this is how it works:

SQL> select * 
  2  from table(get_emp_dets(10))
  3  /

     EMPNO ENAME                          JOB
---------- ------------------------------ --------------------
      7782 CLARK                          MANAGER
      7839 KING                           PRESIDENT
      7934 MILLER                         CLERK

SQL> 

SQL Types offer us a great deal of functionality, and allow us to build quite sophisticated APIs in PL/SQL. Find out more.