在SQLServer中我們可以用over子句中來代替子查詢實現來提高效率,over子句除了排名函數之外也可以和聚合函數配合。實現代碼如下：
代碼如下：
use tempdb
go
if (object_id ('tb' ) is not null )
drop table tb
go
create table tb (name varchar (10 ), val int )
go
insert into tb
select 'aa' , 10
union all select 'aa' , 20
union all select 'aa' , 20
union all select 'aa' , 30
union all select 'bb' , 55
union all select 'bb' , 45
union all select 'bb' , 0
select *
, 排名 = rank ()over (partition by name order by val )
, 占比 = cast (val * 1.0 / sum (val )over (partition by name ) as decimal (2 , 2 ))
, 距最大 = val - max (val )over (partition by name )
, 距最小 = val - min (val )over (partition by name )
, 距平均 = val - avg (val )over (partition by name )
from tb
