Writing a function to find whether a value is present in a sql query output

Question

Hi gurus,
I would like to write a function to which i will pass a value and a sql query as parameters.
Now the function needs to execute that sql query and find whether the given value is present in the output list
when the query is executed. If it is present it should return 'T' otherwise 'F'
My function will look like
CREATE FUNCTION CHECK_VALUE(VALUE VARCHAR2,V_SQL VARCHAR2) RETURN VARCHAR2
SELECT CHECK_VALUE('Dallas','SELECT LOCATION_CODE FROM HR_LOCATIONS')
It should check whether the value 'Dallas' is present in the output list returned by the sql query.
Any help will be appreciated.
Thank you.

Answer 1

CREATE OR REPLACE
  FUNCTION CHECK_VALUE(
                       VALUE VARCHAR2,
                       V_SQL VARCHAR2
    RETURN VARCHAR2
    IS
        RETVAL VARCHAR2(4000);
        REFCUR SYS_REFCURSOR;
    BEGIN
        OPEN REFCUR FOR V_SQL;
        LOOP
          FETCH REFCUR INTO RETVAL;
          EXIT WHEN REFCUR%NOTFOUND;
          IF RETVAL = VALUE
            THEN
              CLOSE REFCUR;
              RETURN 'T';
          END IF;
        END LOOP;
        CLOSE REFCUR;
        RETURN 'F';
END;
Function created.
SQL> SET SERVEROUTPUT ON
SQL> EXEC DBMS_OUTPUT.PUT_LINE(CHECK_VALUE('DALLAS','select loc from dept'));
T
PL/SQL procedure successfully completed.
SQL> EXEC DBMS_OUTPUT.PUT_LINE(CHECK_VALUE('PARIS','select loc from dept'));
F
PL/SQL procedure successfully completed.
SQL> SY.