DECLARE
    points NUMBER;

    CURSOR all_student_ids IS SELECT s.ID_STUDENT FROM STUDENCI s;

    FUNCTION get_student_score (p_id_student NUMBER) RETURN NUMBER IS
        score NUMBER;
        BEGIN
            SELECT NVL(SUM(punkty), 0) INTO score FROM egzaminy WHERE ID_STUDENT = p_id_student;
            RETURN score;
        END get_student_score;

BEGIN
    FOR student IN all_student_ids LOOP
        points := get_student_score(student.id_student);
        IF points != 0 THEN
            DBMS_OUTPUT.put_line('Suma punktów studenta o ID ' || student.id_student || ': ' || points);
        ELSE
            DBMS_OUTPUT.put_line('Student o ID ' || student.id_student || ' nie zdawał egzaminu');
        END IF;
    END LOOP;
END;