MSSQL示例（三）ROWNUMBER、RANK、DENSE_RANK、NTILE排名窗口函数示例

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-- Author:  tomtom
-- Create date: 2015.2.27
-- Description: ROWNUMBER、RANK、DENSE_RANK、NTILE排名窗口函数示例
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/*1.准备数据(去掉注释再执行--!)
create table t1
(
id int identity(1,1) primary key,
name varchar(50),
qty int default(0)
)
go


insert into t1(name,qty) select ‘a1‘,1
insert into t1(name,qty) select ‘a3‘,3
insert into t1(name,qty) select ‘a2‘,2
insert into t1(name,qty) select ‘a5‘,5
insert into t1(name,qty) select ‘a2‘,22
insert into t1(name,qty) select ‘a2‘,21
insert into t1(name,qty) select ‘a2‘,20
insert into t1(name,qty) select ‘a1‘,11
insert into t1(name,qty) select ‘a1‘,12
insert into t1(name,qty) select ‘a5‘,50


select * from t1
*/


/*2.1示例 OVER+ODER BY*/
select t1.*
,ROW_NUMBER() OVER( ORDER BY name,id) as ‘ROW_NUMBER‘ 
,ROW_NUMBER() OVER( ORDER BY name desc,id desc) as ‘ROW_NUMBER_DESC‘ 
,RANK() OVER( ORDER BY name) as ‘RANK‘ 
,RANK() OVER( ORDER BY name,id) as ‘RANK_name_id‘ 
,DENSE_RANK() OVER( ORDER BY name) as ‘DENSE_RANK‘ 
,t1.name
,NTILE(1) OVER( ORDER BY name,id) as ‘NTILE_1group‘ 
,NTILE(2) OVER( ORDER BY name,id) as ‘NTILE_2g‘ 
,NTILE(3) OVER( ORDER BY name,id) as ‘NTILE_3g‘ 
,NTILE(4) OVER( ORDER BY name,id) as ‘NTILE_4g‘
--NTILE(分组数目)平均有余时，从最后的组倒分平均：avg=2 for 4,avg=2 for 3,avg=3 for 2 and 1
from t1
order by t1.name,id


/*2.2示例 OVER + PATITION BY + ODER BY*/
--加了PATITION，将会先PATITION成多个分区，然后在分区内部排名，各区的排名互不干扰，排名计数器各自独立从0开始
select t1.*
,ROW_NUMBER() OVER( PARTITION BY name ORDER BY name,id ) as ‘ROW_NUMBER‘ 
,ROW_NUMBER() OVER( PARTITION BY name ORDER BY name desc,id desc) as ‘ROW_NUMBER_DESC‘ 
,RANK() OVER( PARTITION BY name ORDER BY name) as ‘RANK‘ 
,RANK() OVER( PARTITION BY name ORDER BY name,id) as ‘RANK_name_id‘ 
,DENSE_RANK() OVER( PARTITION BY name ORDER BY name) as ‘DENSE_RANK‘ 
,t1.name
,NTILE(1) OVER( PARTITION BY name ORDER BY name,id) as ‘NTILE_1group‘ 
,NTILE(2) OVER( PARTITION BY name ORDER BY name,id) as ‘NTILE_2g‘ 
,NTILE(3) OVER( PARTITION BY name ORDER BY name,id) as ‘NTILE_3g‘ 
,NTILE(4) OVER( PARTITION BY name ORDER BY name,id) as ‘NTILE_4g‘
from t1
order by t1.name,id