创建存储过程proc1，输入某同学的学号，使用游标统计该同学的平均分，并返回平均分，同时显示该同学的姓名、课程名称和选课成绩。

CREATE PROCEDURE proc1(IN student_id INT)
BEGIN
    DECLARE done INT DEFAULT 0;
    DECLARE sName VARCHAR(255);
    DECLARE cName VARCHAR(255);
    DECLARE score INT;
    DECLARE cur CURSOR FOR 
        SELECT student_name, course_name, course_score
        FROM student_courses
        WHERE student_id = student_id;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
    OPEN cur;
    read_loop: LOOP
        FETCH cur INTO sName, cName, score;
        IF done THEN
            LEAVE read_loop;
        END IF;
        -- 逐行显示同学的姓名，课程名，成绩
        SELECT sName, cName, score;
    END LOOP;
    CLOSE cur;
    -- 统计该同学的平均分并返回
    SELECT AVG(course_score) AS average_score
    FROM student_courses
    WHERE student_id = student_id;
END;