2020-09-06 阅读量: 883
select *
from
(select *
from sc
left join student on sc.sno=student.sno ) t
left join course on t.cno=course.cno
where student.sdept='计算机系' or student.sdept='信息系'
order by student.sdept,student.sname,student.ssex,course.cname, sc.grade;
为什么会报错？
Error Code: 1060. Duplicate column name 'sno'
