查询课程数mysql_mysql_数据查询练习
course:teachar:studentsc:1、查询“c001”课程比“c002”课程成绩高的所有学生的学号;select a.sid from(select sid,score from sc where cid=001) as a,(select sid,score from sc where cid=002) as bwhere a.score > b.score and a.s...