DECLARE
   c_sec_id   NUMBER (5);
BEGIN
   SELECT course_sec.course_sec_id
     INTO c_sec_id
     FROM course_sec, course, term, grades
    WHERE course_sec.course_sec_id = grades.course_sec_id
      AND course.course_id = course_sec.course_id
      AND course_sec.term_id = term.term_id
      AND term_desc = 'SPRING 2006'
      AND course_sec.course_sec_id = :grades.course_sec_id;

   INSERT INTO grades
               (s_id, course_sec_id, grade
               )
        VALUES (:grades.s_id, c_sec_id, :grades.grade
               );
EXCEPTION
   WHEN NO_DATA_FOUND
   THEN
      NULL;
END;