跟几个表没有关系，聚合函数之外的字段，group by 中都要列出如student,scoreselect a.sno,a.sname,sum(b.value) from student a,score bwhere a.sno=b.snogroup by a.sno,a.sname a.sno,a.sname 必须出现在group by 中
同意上楼的
