关于#MySQL#的问题，如何解决？（相关搜索：存储过程）

Question

创建存储过程查询指定学生成绩单
delimter＄
CREATE PROCEDURE pro_grade(
    IN id VARCHAR(30),
    IN name VARCHAR(30)
)
BEGIN
    IF id IS NULL OR name IS NULL THEN
        SELECT '请输入学号与姓名！';
    ELSEIF (
        (SELECT name FROM Student WHERE id = id) != name
        OR (SELECT id FROM Student WHERE name = name) != id
    ) THEN
        SELECT '输入有误！';
    ELSE
        SELECT Student.id, name, Kname, Ggrade
        FROM Student, Grade, Course
        WHERE Student.id = Grade.id
        AND Grade.Kid = Course.Kid
        AND name = name;
    END IF;
END ＄
delimter；
请问为啥出错啊

改成这样对吗？
DELIMITER $

CREATE PROCEDURE pro_grade(
    IN p_id VARCHAR(30),
    IN p_name VARCHAR(30)
)
BEGIN
    DECLARE v_name VARCHAR(30);
    DECLARE v_id VARCHAR(30);

    IF p_id IS NULL OR p_name IS NULL THEN
        SELECT '请输入学号与姓名！';
    ELSE
        SELECT id INTO v_id, name INTO v_name
        FROM Student 
        WHERE id = p_id AND name = p_name;

        IF v_id IS NULL OR v_name IS NULL THEN
            SELECT '输入有误！';
        ELSE
            SELECT Student.id, name, Kname, Ggrade
            FROM Student
            JOIN Grade ON Student.id = Grade.id
            JOIN Course ON Grade.Kid = Course.Kid
            WHERE name = p_name;
        END IF;
    END IF;
END $

DELIMITER ;

Answer 1

出现错误的原因是因为你在第一段代码中使用了错误的语法。以下是修正后的正确代码：

DELIMITER $

CREATE PROCEDURE pro_grade(
    IN p_id VARCHAR(30),
    IN p_name VARCHAR(30)
)
BEGIN
    IF p_id IS NULL OR p_name IS NULL THEN
        SELECT '请输入学号与姓名！';
    ELSEIF (
        (SELECT name FROM Student WHERE id = p_id) != p_name
        OR (SELECT id FROM Student WHERE name = p_name) != p_id
    ) THEN
        SELECT '输入有误！';
    ELSE
        SELECT Student.id, name, Kname, Ggrade
        FROM Student, Grade, Course
        WHERE Student.id = Grade.id
        AND Grade.Kid = Course.Kid
        AND name = p_name;
    END IF;
END $

DELIMITER ;