mysql查询（六）

查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩

总数：count()          总分：sum()           排序：ORDER BY        分组：group by

命令：SELECT DISTINCT a.Sid,a.Sname,a.Sage,a.Ssex,b.Cid,b.score from ex_xueshengbiao_95 a 

left join (select  Sid,count(1) as 'Cid',sum(score) as 'score' from ex_chengjibiao_95 group by sid) b 

on a.Sid=b.Sid ORDER BY a.Sid