说明: 摘要: -- 1、查询“01”课程比“02”课程成绩高的所有学生的学号; SELECT a.sid FROM (SELECT sid, score FROM sc WHERE cid=01) a, (SELECT sid ,score FROM sc WHERE cid=02) b WHERE a.score > b.score AND a.sid= b.sid; SELECT a.sid FROM student a LEFT JOIN SC b ON b.cid=01 AND a.s <oneeyear> 上传 | 大小:18kb