查出每个班级的总分前两名的学生
生信息表:students 学生编号 学生姓名 学生所班级id name class001 学生一 class_01
002 学生二 class_01003 学生三 class_01004 学生四 class_02005 学生五 class_02006 学生六 class_02
成绩表:results学生编号 科目名称 分数 id course_name course_score001 语文 80
002 语文 80
003 语文 83
004 语文 80
005 语文 80
006 语文 60
001 数学 80
002 数学 80
003 数学 60
004 数学 80
005 数学 80
006 数学 82
001 外语 80
002 外语 80
003 外语 60
004 外语 80
005 外语 80
006 外语 75
怎么用sql server 查出每个班级的总分前两名的学生?
生信息表:students 学生编号 学生姓名 学生所班级id name class001 学生一 class_01
002 学生二 class_01003 学生三 class_01004 学生四 class_02005 学生五 class_02006 学生六 class_02
成绩表:results学生编号 科目名称 分数 id course_name course_score001 语文 80
002 语文 80
003 语文 83
004 语文 80
005 语文 80
006 语文 60
001 数学 80
002 数学 80
003 数学 60
004 数学 80
005 数学 80
006 数学 82
001 外语 80
002 外语 80
003 外语 60
004 外语 80
005 外语 80
006 外语 75
怎么用sql server 查出每个班级的总分前两名的学生?
/*
数据如下:
name val memo
a 2 a2(a的第二个值)
a 1 a1--a的第一个值
a 3 a3:a的第三个值
b 1 b1--b的第一个值
b 3 b3:b的第三个值
b 2 b2b2b2b2
b 4 b4b4
b 5 b5b5b5b5b5
*/
--创建表并插入数据:
create table tb(name varchar(10),val int,memo varchar(20))
insert into tb values('a', 2, 'a2(a的第二个值)')
insert into tb values('a', 1, 'a1--a的第一个值')
insert into tb values('a', 3, 'a3:a的第三个值')
insert into tb values('b', 1, 'b1--b的第一个值')
insert into tb values('b', 3, 'b3:b的第三个值')
insert into tb values('b', 2, 'b2b2b2b2')
insert into tb values('b', 4, 'b4b4')
insert into tb values('b', 5, 'b5b5b5b5b5')
go--一、按name分组取val最大的值所在行的数据。
--方法1:
select a.* from tb a where val = (select max(val) from tb where name = a.name) order by a.name
--方法2:
select a.* from tb a where not exists(select 1 from tb where name = a.name and val > a.val)
--方法3:
select a.* from tb a,(select name,max(val) val from tb group by name) b where a.name = b.name and a.val = b.val order by a.name
--方法4:
select a.* from tb a inner join (select name , max(val) val from tb group by name) b on a.name = b.name and a.val = b.val order by a.name
--方法5
select a.* from tb a where 1 > (select count(*) from tb where name = a.name and val > a.val ) order by a.name
/*
name val memo
---------- ----------- --------------------
a 3 a3:a的第三个值
b 5 b5b5b5b5b5
*/--二、按name分组取val最小的值所在行的数据。
--方法1:
select a.* from tb a where val = (select min(val) from tb where name = a.name) order by a.name
--方法2:
select a.* from tb a where not exists(select 1 from tb where name = a.name and val < a.val)
--方法3:
select a.* from tb a,(select name,min(val) val from tb group by name) b where a.name = b.name and a.val = b.val order by a.name
--方法4:
select a.* from tb a inner join (select name , min(val) val from tb group by name) b on a.name = b.name and a.val = b.val order by a.name
--方法5
select a.* from tb a where 1 > (select count(*) from tb where name = a.name and val < a.val) order by a.name
/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 1 b1--b的第一个值
*/--三、按name分组取第一次出现的行所在的数据。
select a.* from tb a where val = (select top 1 val from tb where name = a.name) order by a.name
/*
name val memo
---------- ----------- --------------------
a 2 a2(a的第二个值)
b 1 b1--b的第一个值
*/--四、按name分组随机取一条数据。
select a.* from tb a where val = (select top 1 val from tb where name = a.name order by newid()) order by a.name
/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 5 b5b5b5b5b5
*/--五、按name分组取最小的两个(N个)val
select a.* from tb a where 2 > (select count(*) from tb where name = a.name and val < a.val ) order by a.name,a.val
select a.* from tb a where val in (select top 2 val from tb where name=a.name order by val) order by a.name,a.val
select a.* from tb a where exists (select count(*) from tb where name = a.name and val < a.val having Count(*) < 2) order by a.name
/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
a 2 a2(a的第二个值)
b 1 b1--b的第一个值
b 2 b2b2b2b2
*/--六、按name分组取最大的两个(N个)val
select a.* from tb a where 2 > (select count(*) from tb where name = a.name and val > a.val ) order by a.name,a.val
select a.* from tb a where val in (select top 2 val from tb where name=a.name order by val desc) order by a.name,a.val
select a.* from tb a where exists (select count(*) from tb where name = a.name and val > a.val having Count(*) < 2) order by a.name
/*
name val memo
---------- ----------- --------------------
a 2 a2(a的第二个值)
a 3 a3:a的第三个值
b 4 b4b4
b 5 b5b5b5b5b5
*/
insert into students values('001','学生一','class_01')
insert into students values('002','学生二','class_01')
insert into students values('003','学生三','class_01')
insert into students values('004','学生四','class_02')
insert into students values('005','学生五','class_02')
insert into students values('006','学生六','class_02')
create table results(id varchar(10),course_name varchar(10),course_score int)
insert into results values('001','语文',80)
insert into results values('002','语文',80)
insert into results values('003','语文',83)
insert into results values('004','语文',80)
insert into results values('005','语文',80)
insert into results values('006','语文',60)
insert into results values('001','数学',80)
insert into results values('002','数学',80)
insert into results values('003','数学',60)
insert into results values('004','数学',80)
insert into results values('005','数学',80)
insert into results values('006','数学',82)
insert into results values('001','外语',80)
insert into results values('002','外语',80)
insert into results values('003','外语',60)
insert into results values('004','外语',80)
insert into results values('005','外语',80)
insert into results values('006','外语',75)
goselect m.* from (select a.class , a.id , course_score = sum(b.course_score) from students a,results b where a.id = b.id group by a.class , a.id) m
where 2 > (select count(*) from (select a.class , a.id , course_score = sum(b.course_score) from students a,results b where a.id = b.id group by a.class , a.id) n where n.class = m.class and n.course_score > m.course_score )
order by m.class , m.course_score desc , m.iddrop table students,results/*
class id course_score
---------- ---------- ------------
class_01 001 240
class_01 002 240
class_02 004 240
class_02 005 240(所影响的行数为 4 行)
*/
select m.* from (select a.class , a.id , course_score = sum(b.course_score) from students a,results b where a.id = b.id group by a.class , a.id) m
where 2 > (select count(*) from (select a.class , a.id , course_score = sum(b.course_score) from students a,results b where a.id = b.id group by a.class , a.id) n where n.class = m.class and n.course_score > m.course_score )
order by m.class , m.course_score desc , m.id
借潇洒老乌龟数据一用
create table students(id varchar(10),cname varchar(10),class varchar(10))
insert into students values('001','学生一','class_01')
insert into students values('002','学生二','class_01')
insert into students values('003','学生三','class_01')
insert into students values('004','学生四','class_02')
insert into students values('005','学生五','class_02')
insert into students values('006','学生六','class_02')
create table results(id varchar(10),course_name varchar(10),course_score int)
insert into results values('001','语文',80)
insert into results values('002','语文',80)
insert into results values('003','语文',83)
insert into results values('004','语文',80)
insert into results values('005','语文',80)
insert into results values('006','语文',60)
insert into results values('001','数学',80)
insert into results values('002','数学',80)
insert into results values('003','数学',60)
insert into results values('004','数学',80)
insert into results values('005','数学',80)
insert into results values('006','数学',82)
insert into results values('001','外语',80)
insert into results values('002','外语',80)
insert into results values('003','外语',60)
insert into results values('004','外语',80)
insert into results values('005','外语',80)
insert into results values('006','外语',75) select top 4
a.class,b.id,sum(b.course_score)as score
from students a left join results b
on a.id=b.id
group by a.class,b.id
order by sum(b.course_score) desc,a.class/*
class id score
---------- ---------- -----------
class_01 002 240
class_01 001 240
class_02 005 240
class_02 004 240(所影响的行数为 4 行)
*/