Fehler in PL/SQL-Code für Cursor

Question

Declare 
     vStudent_id  grade.student_id%TYPE; 
     vSection_id  grade.section_id%TYPE; 
     vNumeric_grade grade.numeric_grade%TYPE; 

     CURSOR gradeCursor IS 
      SELECT student_id,section_id,numeric_grade 
      FROM grade 
      WHERE student_id = 102 
      ORDER by numeric_grade; 
Begin 
    Open gradeCursor; 
    LOOP 

    FETCH gradeCursor 
      INTO vStudent_id,vSection_id,vNumeric_grade; 
    EXIT WHEN gradeCursor%NOTFOUND; 


    DBMS_OUTPUT.PUT_LINE('Student number: ' || vStudent_id); 
    DBMS_OUTPUT.PUT_LINE('Section_id: ' || vSection_id); 
    IF numeric_grade IS NOT NULL THEN 
        DBMS_OUTPUT.PUT_LINE('Numeric Grade: ' || vNumeric_grade); 
    ELSE 
        DBMS_OUTPUT.PUT_LINE('Numeric Grade: NULL'); 
    END IF; 
    END LOOP; 
    IF gradeCursor%ISOPEN THEN CLOSE gradeCursor; END IF; 

    EXCEPTION 
    WHEN OTHERS THEN 
      DBMS_OUTPUT.PUT_LINE('Error dected'); 
      IF gradeCursor%ISOPEN THEN CLOSE gradeCursor; END IF; 
END; 

Answer 1

Ihr Code kann leicht durch Ausschließen impliziter Cursor und alle vereinfacht werden. Sie können problemlos die FOR-Schleife verwenden, um Ihren Anforderungen zu genügen. Hoffnung unter Code hilft.

DECLARE 
    vStudent_id grade.student_id%TYPE; 
    vSection_id grade.section_id%TYPE; 
    vNumeric_grade grade.numeric_grade%TYPE; 
BEGIN 
    FOR I IN 
    (SELECT student_id, 
    section_id, 
    numeric_grade 
    FROM grade 
    WHERE student_id = 102 
    ORDER BY numeric_grade 
) 
    LOOP 
    DBMS_OUTPUT.PUT_LINE('Student number: ' || i.student_id); 
    DBMS_OUTPUT.PUT_LINE('Section_id: ' || i.section_id); 
    IF i.numeric_grade IS NOT NULL THEN 
     DBMS_OUTPUT.PUT_LINE('Numeric Grade: ' || i.numeric_grade); 
    ELSE 
     DBMS_OUTPUT.PUT_LINE('Numeric Grade: NULL'); 
    END IF; 
    END LOOP; 
EXCEPTION 
WHEN OTHERS THEN 
    DBMS_OUTPUT.PUT_LINE('Error dected'); 
END;