Here is how i tested ref cursors in pl/sql developer:
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CREATE OR REPLACE PACKAGE test_ref_cur IS
-- Author : CRUEPPRICH
-- Created : 10/20/2005 8:48:38 AM
-- Purpose :
TYPE g_emp_rec_type IS RECORD(
empno NUMBER(4)
,ename VARCHAR(10));
TYPE g_emp_cur IS REF CURSOR RETURN g_emp_rec_type;
PROCEDURE get_emp_records(p_deptno IN NUMBER
,p_emp_cur IN OUT g_emp_cur);
END test_ref_cur;
/
CREATE OR REPLACE PACKAGE BODY test_ref_cur IS
PROCEDURE get_emp_records(p_deptno IN NUMBER
,p_emp_cur IN OUT g_emp_cur) IS
BEGIN
OPEN p_emp_cur FOR
SELECT empno
,ename
FROM scott.emp
WHERE deptno = p_deptno;
END get_emp_records;
END test_ref_cur;
/
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Now create a test script by right clicking on the get_emp_records procedure:
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begin
-- Call the procedure
test_ref_cur.get_emp_records(p_deptno =>

_deptno,
p_emp_cur =>

_emp_cur);
end;
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After you execute the test script, the 'value' column on the p_emp_cur row will contain the value ''. You will also see a little button in that grid box. Click the button and a new window will pop up with the contents of the cursor.
Pretty nifty.
Christoph