How to pass strings for IN Clause in REF Cursor

Question

I have following query;
SELECT 1 INTO L
FROM test_po_apprvlines
where '4020' between NVL(approval_cost_centre_from, '0000') and
nvl (approval_cost_centre_to, '9999')
and req_approval_type IN ('BUS', 'FIN') and 10500 >= approval_amount
and NVL(req_line_type, 'X') = 'X'
AND ROWNUM =1;
Now the values for req_approval_type should be dynamic, based on approval_amount. If approval_amout > 10000 then
req_approval_type should have 'BUS' and 'FIN' , other wise only 'BUS'.
I have tried with the following code using ref cursor. But i'm not getting the result.
Any help. The problem is how to concatenate those two values to get the result.
in the following code, strings are not recoginised properly. Valid data exists in the table.
DECLARE
l_approva_type1 VARCHAR2(20) := 'FIN';
l_approva_type2 VARCHAR2(10) := 'BUS';
l_approva_type VARCHAR2(20) := '''FIN'''||','||'''BUS''';
L NUMBER;
TYPE TEST_REF IS REF CURSOR;
cur_ref TEST_REF;
L_str varchar2(1000) := 'SELECT 1'||
' FROM test_po_apprvlines'
||' where '||'''4020'''||' between NVL(approval_cost_centre_from, '||'''0000'''||') and nvl(approval_cost_centre_to, '|| '''9999'''||')'
||' and req_approval_type IN ( :bi_approva_type)'||
' and 10500 >= approval_amount '||
' and req_line_type IS NULL '||
'AND ROWNUM =1';
L_flg varchar2(1);
BEGIN
DBMS_OUTPUT.PUT_LINE (l_approva_type);
open cur_ref for l_str USING l_approva_type;
fetch cur_ref INTO l_flg;
close cur_ref;
DBMS_OUTPUT.PUT_LINE (nvl(L_flg, 'x'));
EXCEPTION
WHEN OTHERS THEN
if cur_ref%isopen then
     close cur_ref;
     end if;
DBMS_OUTPUT.PUT_LINE (SQLERRM);
END;

Answer 1

You cant "Bind" here.
One way..
SQL> var a refcursor
SQL> declare
  2   str varchar2(100) := '''SALESMAN'',''ANALYST''';
  3  begin
  4   open :a for 'select ename from emp
  5                where job in ('||str||')';
  6  end;
  7  /
PL/SQL procedure successfully completed.
SQL> print :a
ENAME
WARD
SCOTT
Message was edited by:
        jeneesh
Results in More parsing...