22,209
社区成员
发帖
与我相关
我的任务
分享求一条sql语句分类返回前n条记录
源表:
Id Category AddedDate
1 1 2008-1-2
2 1 2008-1-2
3 1 2008-1-2
4 1 2008-1-3
5 1 2008-1-3
6 2 2008-1-3
7 2 2008-1-3
8 2 2008-1-3
9 2 2008-1-3
10 2 2008-1-3
返回相同Category中的前3条
结果集:
Id Category AddedDate
1 1 2008-1-2
2 1 2008-1-2
3 1 2008-1-2
6 2 2008-1-3
7 2 2008-1-3
8 2 2008-1-3
Id Category AddedDate
1 1 2008-1-2
2 1 2008-1-2
3 1 2008-1-2
4 1 2008-1-3
5 1 2008-1-3
6 2 2008-1-3
7 2 2008-1-3
8 2 2008-1-3
9 2 2008-1-3
10 2 2008-1-3
返回相同Category中的前3条
结果集:
Id Category AddedDate
1 1 2008-1-2
2 1 2008-1-2
3 1 2008-1-2
6 2 2008-1-3
7 2 2008-1-3
8 2 2008-1-3
...全文
请发表友善的回复…
发表回复
hyqwan11112 2008-10-05
- 打赏
- 举报
create table 表(Id int, Category int, AddedDate datetime)
insert into 表
select 1 ,1 ,'2008-1-2' union all
select 2 ,1 ,'2008-1-2' union all
select 3 ,1 ,'2008-1-2' union all
select 4 ,1 ,'2008-1-3' union all
select 5 ,1 ,'2008-1-3' union all
select 6 ,2 ,'2008-1-3' union all
select 7 ,2 ,'2008-1-3' union all
select 8 ,2 ,'2008-1-3' union all
select 9 ,2 ,'2008-1-3' union all
select 10 ,2 ,'2008-1-3'
go
--sql server 2000
select a.* from 表 a
where 3 > (select count(*) from 表 where Category = a.Category and id < a.id )
order by a.Category,a.id
--sql server 2005及以后
select ID,Category,AddedDate
from
(
select *,rowid=ROW_NUMBER() over(partition by Category order by AddedDate)
from 表
) t
where rowid<=3
drop table 表
fcuandy 2008-10-05
- 打赏
- 举报
http://topic.csdn.net/u/20080123/18/9731d130-0d4b-4c11-8d89-f2c3ca331f0c.html
Limpire 2008-10-05
- 打赏
- 举报
路过
tianhuo_soft 2008-10-04
- 打赏
- 举报
create table tb(Id int, Category int, AddedDate datetime)
insert into tb values(1 , 1 , '2008-1-2')
insert into tb values(2 , 1 , '2008-1-2')
insert into tb values(3 , 1 , '2008-1-2')
insert into tb values(4 , 1 , '2008-1-3')
insert into tb values(5 , 1 , '2008-1-3')
insert into tb values(6 , 2 , '2008-1-3')
insert into tb values(7 , 2 , '2008-1-3')
insert into tb values(8 , 2 , '2008-1-3')
insert into tb values(9 , 2 , '2008-1-3')
insert into tb values(10, 2 , '2008-1-3')
go
select a.* from tb a where 3 > (select count(*) from tb where Category = a.Category and id < a.id ) order by a.Category,a.id
tianhxk 2008-10-04
- 打赏
- 举报
[Quote=引用 4 楼 liangCK 的回复:]
SQL code
SELECT *
FROM
(
SELECT *,RID=ROW_NUMBER() OVER(PARTITION BY Category ORDER BY AddedDate)
FROM tb_name
) AS t
WHERE RID<=3
[/Quote]
Sql server2005支持,sql server2000不支持!
55555,我原来忘记装sample文件了，现在装不上去了....
SQL code
SELECT *
FROM
(
SELECT *,RID=ROW_NUMBER() OVER(PARTITION BY Category ORDER BY AddedDate)
FROM tb_name
) AS t
WHERE RID<=3
[/Quote]
Sql server2005支持,sql server2000不支持!
55555,我原来忘记装sample文件了，现在装不上去了....
dawugui 2008-10-04
- 打赏
- 举报
create table tb(Id int, Category int, AddedDate datetime)
insert into tb values(1 , 1 , '2008-1-2')
insert into tb values(2 , 1 , '2008-1-2')
insert into tb values(3 , 1 , '2008-1-2')
insert into tb values(4 , 1 , '2008-1-3')
insert into tb values(5 , 1 , '2008-1-3')
insert into tb values(6 , 2 , '2008-1-3')
insert into tb values(7 , 2 , '2008-1-3')
insert into tb values(8 , 2 , '2008-1-3')
insert into tb values(9 , 2 , '2008-1-3')
insert into tb values(10, 2 , '2008-1-3')
go
--按Category分组取id最小的3个ID
select a.* from tb a where 3 > (select count(*) from tb where Category = a.Category and id < a.id ) order by a.Category,a.id
select a.* from tb a where id in (select top 3 id from tb where Category=a.Category order by id) order by a.Category,a.id
select a.* from tb a where exists (select count(*) from tb where Category = a.Category and id < a.id having Count(*) < 3) order by a.Category,a.id
/*
Id Category AddedDate
----------- ----------- ------------------------------------------------------
1 1 2008-01-02 00:00:00.000
2 1 2008-01-02 00:00:00.000
3 1 2008-01-02 00:00:00.000
6 2 2008-01-03 00:00:00.000
7 2 2008-01-03 00:00:00.000
8 2 2008-01-03 00:00:00.000
（所影响的行数为 6 行）
*/
--按Category分组取id最大的3个ID
select a.* from tb a where 3 > (select count(*) from tb where Category = a.Category and id > a.id ) order by a.Category,a.id desc
select a.* from tb a where id in (select top 3 id from tb where Category=a.Category order by id desc) order by a.Category,a.id desc
select a.* from tb a where exists (select count(*) from tb where Category = a.Category and id > a.id having Count(*) < 3) order by a.Category,a.id desc
/*
Id Category AddedDate
----------- ----------- ------------------------------------------------------
5 1 2008-01-03 00:00:00.000
4 1 2008-01-03 00:00:00.000
3 1 2008-01-02 00:00:00.000
10 2 2008-01-03 00:00:00.000
9 2 2008-01-03 00:00:00.000
8 2 2008-01-03 00:00:00.000
（所影响的行数为 6 行）
*/
--按Category分组取id最先出现的3个ID
select a.* from tb a where id in (select top 3 id from tb where Category = a.Category) order by a.Category , a.id
/*
Id Category AddedDate
----------- ----------- ------------------------------------------------------
1 1 2008-01-02 00:00:00.000
2 1 2008-01-02 00:00:00.000
3 1 2008-01-02 00:00:00.000
6 2 2008-01-03 00:00:00.000
7 2 2008-01-03 00:00:00.000
8 2 2008-01-03 00:00:00.000
（所影响的行数为 6 行）
*/
drop table tb
liangCK 2008-10-04
- 打赏
- 举报
SELECT *
FROM
(
SELECT *,RID=ROW_NUMBER() OVER(PARTITION BY Category ORDER BY AddedDate)
FROM tb_name
) AS t
WHERE RID<=3dawugui 2008-10-04
- 打赏
- 举报
create table tb(Id int, Category int, AddedDate datetime)
insert into tb values(1 , 1 , '2008-1-2')
insert into tb values(2 , 1 , '2008-1-2')
insert into tb values(3 , 1 , '2008-1-2')
insert into tb values(4 , 1 , '2008-1-3')
insert into tb values(5 , 1 , '2008-1-3')
insert into tb values(6 , 2 , '2008-1-3')
insert into tb values(7 , 2 , '2008-1-3')
insert into tb values(8 , 2 , '2008-1-3')
insert into tb values(9 , 2 , '2008-1-3')
insert into tb values(10, 2 , '2008-1-3')
go
select a.* from tb a where 3 > (select count(*) from tb where Category = a.Category and id < a.id ) order by a.Category,a.id
drop table tb
/*
Id Category AddedDate
----------- ----------- ------------------------------------------------------
1 1 2008-01-02 00:00:00.000
2 1 2008-01-02 00:00:00.000
3 1 2008-01-02 00:00:00.000
6 2 2008-01-03 00:00:00.000
7 2 2008-01-03 00:00:00.000
8 2 2008-01-03 00:00:00.000
（所影响的行数为 6 行）
*/dawugui 2008-10-04
- 打赏
- 举报
按日期取最小的三条?
wzy_love_sly 2008-10-04
- 打赏
- 举报
--按某一字段分组取最大(小)值所在行的数据(2007-10-23于浙江杭州)
/*
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
*/
