https://blog.csdn.net/mrbcy/article/details/68965271 经典例题 19.查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录. SELECT s1.Sno,s1.Degree FROM Scores AS s1 INNER JOIN Scores AS s2 ON(s1.Cno=s2.Cno AND s1.Degree>s2.Degree) WHERE s1.Cno='3-105' AND s2.Sno='109' ORDER…