Ref cursor switch based on condition

DECLARE
   a          NUMBER := 3333;
   TYPE rc IS REF CURSOR; -- ref cursor declare
   l_cursor   rc;
   l_ename    emp.ename%TYPE;
   l_deptno   dept.deptno%TYPE;
   l_value    NUMBER;
BEGIN
   IF (a = 30)
   THEN
      OPEN l_cursor FOR 'select ename from emp'; -- opening the cursor for query
      FETCH l_cursor INTO l_ename;
      CLOSE l_cursor;
      DBMS_OUTPUT.put_line ('l_ename : = ' || l_ename);
   ELSIF (a = 20)
   THEN
      OPEN l_cursor FOR SELECT deptno FROM dept;
      FETCH l_cursor INTO l_deptno;
      CLOSE l_cursor;
      DBMS_OUTPUT.put_line ('l_deptno : = ' || l_deptno);
   ELSE
      OPEN l_cursor FOR SELECT 1 FROM DUAL;
      FETCH l_cursor INTO l_value;
      CLOSE l_cursor;
      DBMS_OUTPUT.put_line ('l_value : = ' || l_value);
   END IF;
END;
/