select * from ta t where not exists(select 1 from ta where nick=a.nick and data>t.data )
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select * from [Table] a where not exists(select 1 from [Table] where nick=a.nick and data>a.data)
/*
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 tb values('a', 1000 , 10 )
insert into tb values('a', 1100 , 1 )
insert into tb values('b', 1200 , 10 )
insert into tb values('c', 1000 , 20 )
goselect a.* from tb a where data1 = (select max(data1) from tb where nick = a.nick) order by a.nick
/*
nick data data1
---------- ----------- -----------
a 1000 10
b 1200 10
c 1000 20(所影响的行数为 3 行)
*/select a.* from tb a where data1 = (select min(data1) from tb where nick = a.nick) order by a.nick
/*
nick data data1
---------- ----------- -----------
a 1100 1
b 1200 10
c 1000 20(所影响的行数为 3 行)
*/drop table tb
create table tb(nick varchar(10), data int, data1 int)
insert into tb values('a', 1000 , 10 )
insert into tb values('a', 1100 , 1 )
insert into tb values('b', 1200 , 10 )
insert into tb values('c', 1000 , 20 )
goselect a.* from tb a where data = (select max(data) from tb where nick = a.nick) order by a.nick
/*
nick data data1
---------- ----------- -----------
a 1100 1
b 1200 10
c 1000 20(所影响的行数为 3 行)
*/select a.* from tb a where data = (select min(data) from tb where nick = a.nick) order by a.nick
/*
nick data data1
---------- ----------- -----------
a 1000 10
b 1200 10
c 1000 20(所影响的行数为 3 行)
*/drop table tb
create table tb(nick varchar(10), data int, data1 int)
insert into tb values('a', 1000 , 10 )
insert into tb values('a', 1100 , 1 )
insert into tb values('b', 1200 , 10 )
insert into tb values('c', 1000 , 20 )
goselect a.* from tb a where data1 = (select max(data1) from tb where data = a.data) order by a.data
/*
nick data data1
---------- ----------- -----------
c 1000 20
a 1100 1
b 1200 10(所影响的行数为 3 行)
*/select a.* from tb a where data1 = (select min(data1) from tb where data = a.data) order by a.data
/*
nick data data1
---------- ----------- -----------
a 1000 10
a 1100 1
b 1200 10(所影响的行数为 3 行)
*/drop table tb
nick data data1
a 1000 10
a 1100 1
a 1000 5
a 1100 2
b 1200 10
c 1100 2
c 1000 20说明一下,要统计这张表中data字段最高的和其所对应的data1的合集,
如果出现data值相同,还要按data1的大小返回我自己写了一下
select nick,max(data) as tmp,max(data1) as tmp1 from testtable group by nick order by data desc,data1 desc
得到的结果
nick tmp tmp1
b 1200 10
a 1100 3
c 1100 2希望得到的结果nick tmp tmp1
b 1200 10
a 1100 3
c 1100 2
希望大家帮忙!!先谢了!
from testtable t where
data=(select max(data) from testtable where nick=t.nick)
group by nick,data