How to call a function in a package

Question

I'm doing the following but it doesnt work

select package_name.function_name(param,param) from dual

I'm calling a function that returns a cursor so im guessing "from dual" is the problem

is there another way of doing it?

Answer 1

I presume you mean a Ref Cursor. This is a PL/SQL construct which acts as a pointer to a set of records returned by a query. This means it has to be interpreted by the client which runs the query. For instance, we can map a Ref Cursor to a JDBC or ODBC ResultSet.

There is certainly nothing wrong with your basic statement. Here is a function similar to your own:

SQL> desc get_emps
FUNCTION get_emps RETURNS REF CURSOR
 Argument Name                  Type                    In/Out Default?
 ------------------------------ ----------------------- ------ --------
 P_DNO                          NUMBER(2)               IN
 P_SORT_COL                     VARCHAR2                IN     DEFAULT
 P_ASC_DESC                     VARCHAR2                IN     DEFAULT

SQL> 

I can easily call this in a wider PL/SQL block:

SQL> declare
  2      rc sys_refcursor;
  3  begin
  4      rc := get_emps(50);
  5  end;
  6  /

PL/SQL procedure successfully completed.

SQL>

However, SQL*PLus can handle CURSOR constructs natively:

SQL> select get_emps(50) from dual
  2  /

GET_EMPS(50)
--------------------
CURSOR STATEMENT : 1

CURSOR STATEMENT : 1

     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
      8060 VERREYNNE  PLUMBER         8061 08-APR-08       4000                    50
      8061 FEUERSTEIN PLUMBER         7839 27-FEB-10       4500                    50
      8085 TRICHLER   PLUMBER         8061 08-APR-10       3500                    50
      8100 PODER      PLUMBER         8061                 3750                    50


SQL>

This statement also runs in SQL Developer, although the result set is laid out in an ugly fashion.

So, if you are having problems with your function, the questions are:

1. What client environment are you using?
2. In what precise fashion does it "not work"? Please describe the observed behaviour, including any error messages?
3. Also give us environment details such as the version of the database, the OS, etc.

---

Having read your other question on this topic I thought the problem might be due to the use of a User-Defined Ref Cursor (rather than the built-in). However, that doesn't make any difference. This packaged function:

SQL> create or replace package emp_rc_utils as
  2
  3      type emp_rc is ref cursor return emp%rowtype;
  4
  5      function       get_emps
  6          ( p_dno in emp.deptno%type
  7      )
  8      return emp_rc;
  9  end;
 10  /

Package created.

SQL> create or replace package body emp_rc_utils as
  2
  3      function       get_emps
  4          ( p_dno in emp.deptno%type
  5      )
  6          return emp_rc
  7      is
  8          return_value emp_rc_utils.emp_rc;
  9      begin
 10
 11          open return_value for select * from emp where deptno = p_dno;
 12
 13          return return_value;
 14      end get_emps;
 15
 16  end emp_rc_utils;
 17  /

Package body created.

SQL>

Still works...

SQL> declare
  2      rc sys_refcursor;
  3  begin
  4      rc := emp_rc_utils.get_emps(50);
  5  end;
  6  /

PL/SQL procedure successfully completed.


SQL> select emp_rc_utils.get_emps(50) from dual
  2  /

EMP_RC_UTILS.GET_EMP
--------------------
CURSOR STATEMENT : 1

CURSOR STATEMENT : 1

     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
      8085 TRICHLER   PLUMBER         8061 08-APR-10       3500                    50
      8060 VERREYNNE  PLUMBER         8061 08-APR-08       4000                    50
      8061 FEUERSTEIN PLUMBER         7839 27-FEB-10       4500                    50
      8100 PODER      PLUMBER         8061                 3750                    50


SQL>