0 THEN**     **grade := 'FAIL';**     **RETURN grade;**     **ELSE**     **grade := 'Did not appear in exam';**     **RETURN grade;**     **END CASE;**     END;     $$ LANGUAGE plpgsql;  The result with `00` marks can be seen using the following statement:      warehouse_db=# SELECT search_case(00);      search_case      -------------          FAIL         (0 row)  The result with `00` marks can be seen using the following statement:      warehouse_db=# SELECT search_case(00);      search_case      -------------          PASS         (0 row)  ##