-- 41、查询不同课程成绩相同的学生的学生编号、课程编号、学生成绩

SELECT
    s1.*
FROM Score AS s1 INNER JOIN Score AS s2
ON s1.s_id = s2.s_id AND s1.c_id <> s2.c_id AND s1.s_score = s2.s_score;