--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
--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
--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
--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
--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 --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 --七,如果整行数据有重复,所有的列都相同。 --在sql server 2000中只能用一个临时表来解决,生成一个自增列,先对val取最大或最小,然后再通过自增列来取数据。 --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', 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('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 select * , px = identity(int,1,1) into tmp from tb select m.name,m.val,m.memo from ( select t.* from tmp t where val = ( select min(val) from tmp where name = t.name) ) m where px = (select min(px) from ( select t.* from tmp t where val = (select min(val) from tmp where name = t.name) ) n where n.name = m.name) drop table tb,tmp /* name val memo ---------- ----------- -------------------- a 1 a1--a的第一个值 b 1 b1--b的第一个值 (2 行受影响) */ --在sql server 2005中可以使用row_number函数,不需要使用临时表。 --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', 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('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 select m.name,m.val,m.memo from ( select * , px = row_number() over(order by name , val) from tb ) m where px = (select min(px) from ( select * , px = row_number() over(order by name , val) from tb ) n where n.name = m.name) drop table tb /* name val memo ---------- ----------- -------------------- a 1 a1--a的第一个值 b 1 b1--b的第一个值 (2 行受影响) */
create table tb(col int,col1 int,col2 int)--表里面的数据比如是这样, 我想要col里面的数据。 insert into tb select 1,2,4-- select col from thisTable where col2 = 4 and col1 有不同数值, insert into tb select 1,2,4-- 结果应该是1 因为虽然3的col2也等于4 但是col1里面的数据都相同。 insert into tb select 1,3,4-- 这个语句 怎么写那? insert into tb select 2,3,5 insert into tb select 2,3,5 insert into tb select 3,1,4 insert into tb select 3,1,4 go select col from( select distinct col,col1 from tb )t group by col having count(*)>1 go drop table tb /* col ----------- 1(1 行受影响) */
select distinct col from tb where col2=4 and not exists(select 1 from tb t where t.col2=tb.col2 and t.col1=tb.col2)
create table tb3(col int,col1 int,col2 int) insert into tb3 values(1,2,4) insert into tb3 values (1,2,4) insert into tb3 values (1,3,4) insert into tb3 values (2,3,5) insert into tb3 values (2,3,5) insert into tb3 values (3,1,4) insert into tb3 values (3,1,4) insert into tb3 values (4,1,4) insert into tb3 values (4,1,4) insert into tb3 values (4,1,4) insert into tb3 values (4,2,4) go select distinct col from tb3 where col2=4 and col in ( select col from ( select distinct col,col1 from tb3 ) a group by col having count(*)>1 )
SELECT col FROM (SELECT DISTINCT * FROM tb)t WHERE t.col2=4 GROUP BY Col HAVING COUNT(*)>1
--建表 create table #tb(col int,col1 int,col2 int) insert into #tb select 1,2,4 insert into #tb select 1,2,4 insert into #tb select 1,3,4 insert into #tb select 2,3,5 insert into #tb select 2,3,5 insert into #tb select 3,1,4 insert into #tb select 3,1,4 go--查询 SELECT col FROM ( SELECT DISTINCT col,col1 FROM #tb WHERE col2=4 ) a GROUP BY col HAVING COUNT(col1)>1--结果 col 1
create table A ( col int, col1 int, col2 int )insert into A select 1,2,4 union all select 1,3,4 union all select 2,3,5 union all select 2,3,5 union all select 3,1,4 union all select 3,1,4select distinct AA.col from A AA,(select col,count(distinct col1) AS Acount,col2 from A group by col,col2) BB where AA.col=BB.col and AA.col2=BB.col2 and AA.col2=4 and BB.Acount>1
--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
--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
--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
--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
--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 --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 --七,如果整行数据有重复,所有的列都相同。 --在sql server 2000中只能用一个临时表来解决,生成一个自增列,先对val取最大或最小,然后再通过自增列来取数据。
--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', 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('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
select * , px = identity(int,1,1) into tmp from tb
select m.name,m.val,m.memo
from ( select t.* from tmp t where val = (
select min(val) from tmp where name = t.name) ) m
where px = (select min(px) from (
select t.* from tmp t where val = (select min(val) from tmp where name = t.name) ) n
where n.name = m.name) drop table tb,tmp
/* name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 1 b1--b的第一个值
(2 行受影响)
*/
--在sql server 2005中可以使用row_number函数,不需要使用临时表。
--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', 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('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
select m.name,m.val,m.memo
from (
select * , px = row_number() over(order by name , val) from tb ) m
where px = (select min(px) from (
select * , px = row_number() over(order by name , val) from tb ) n
where n.name = m.name)
drop table tb
/* name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 1 b1--b的第一个值
(2 行受影响)
*/
例子是col col1 col2 表里面的数据比如是这样, 我想要col里面的数据。
1 2 4 select col from thisTable where col2 = 4 and col1 有不同数值,
1 2 4 结果应该是1 因为虽然3的col2也等于4 但是col1里面的数据都相同。
1 3 4 这个语句 怎么写那?
2 3 5
2 3 5
3 1 4
3 1 4
insert into tb select 1,2,4-- select col from thisTable where col2 = 4 and col1 有不同数值,
insert into tb select 1,2,4-- 结果应该是1 因为虽然3的col2也等于4 但是col1里面的数据都相同。
insert into tb select 1,3,4-- 这个语句 怎么写那?
insert into tb select 2,3,5
insert into tb select 2,3,5
insert into tb select 3,1,4
insert into tb select 3,1,4
go
select col from(
select distinct col,col1 from tb
)t group by col having count(*)>1
go
drop table tb
/*
col
-----------
1(1 行受影响)
*/
create table tb3(col int,col1 int,col2 int)
insert into tb3 values(1,2,4)
insert into tb3 values (1,2,4)
insert into tb3 values (1,3,4)
insert into tb3 values (2,3,5)
insert into tb3 values (2,3,5)
insert into tb3 values (3,1,4)
insert into tb3 values (3,1,4)
insert into tb3 values (4,1,4)
insert into tb3 values (4,1,4)
insert into tb3 values (4,1,4)
insert into tb3 values (4,2,4)
go
select distinct col from tb3 where col2=4 and col in
(
select col from
(
select distinct col,col1 from tb3
) a
group by col
having count(*)>1
)
SELECT col FROM
(SELECT DISTINCT * FROM tb)t
WHERE t.col2=4
GROUP BY Col
HAVING COUNT(*)>1
--建表
create table #tb(col int,col1 int,col2 int)
insert into #tb select 1,2,4
insert into #tb select 1,2,4
insert into #tb select 1,3,4
insert into #tb select 2,3,5
insert into #tb select 2,3,5
insert into #tb select 3,1,4
insert into #tb select 3,1,4
go--查询
SELECT col FROM (
SELECT DISTINCT col,col1 FROM #tb
WHERE col2=4
) a
GROUP BY col
HAVING COUNT(col1)>1--结果
col
1
(
col int,
col1 int,
col2 int
)insert into A
select 1,2,4
union all
select 1,3,4
union all
select 2,3,5
union all
select 2,3,5
union all
select 3,1,4
union all
select 3,1,4select distinct AA.col
from A AA,(select col,count(distinct col1) AS Acount,col2 from A group by col,col2) BB
where AA.col=BB.col and AA.col2=BB.col2 and AA.col2=4 and BB.Acount>1