select * from
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(select Student.S#,Sname,Sage,Ssex,SC.C#,score,Cname
from SC inner join Student on SC.S#=Student.S#
inner join Course on Course.C#=SC.C#) as t
where exists(
select count(1) from t as d
where C#=d.C# and score d.score
having count(1)3
)
可以用row_number函数来解决。
1、创建测试表，插入数据：
create table sc
(id int,
name varchar(20),
class varchar(20),
score int);
insert into sc values (1,'badkano','一年一班',100)
insert into sc values (2,'百度知道团长','一年一班',99)
insert into sc values (3,'du小短','一年一班',95)
insert into sc values (4,'du小小动','一年一班',97)
insert into sc values (5,'du小智','一年一班',80)
insert into sc values (6,'吕布','一年二班',67)
insert into sc values (7,'赵云','一年二班',90)
insert into sc values (8,'典韦','一年二班',89)
insert into sc values (9,'关羽','一年二班',70)
insert into sc values (10,'马超','一年二班',98)
2、查询每个班级的前三名，可用语句：
select * from
(select row_number() over (partition by class order by score desc) 排名,* from sc) t
where 排名=3 order by class asc,score desc
Try this one,should be fine
下面这个已经有排序了哦，不行么？
SELECT uid, group_concat(subject)
FROM (SELECT id, uid, subject
FROM (SELECT id, uid, subject,
(SELECT COUNT(*)
FROM t_subject
WHERE uid = t.uid
AND subject = t.subject) RK
FROM t_subject t) t1
WHERE rk = 3) t2
GROUP BY uid
多了个a.原来
或者你直接用个substring()得了。。。
