sql over(partition by) 開窗函數的使用

patition by  在group by分組匯總的前提下，再匯總一次

1、patition by 1   匯總所有數據

 select * from stu 

select
class,
sum(score) 班級總分,
sum(sum(score)) over(partition by 1) 年級總分,
cast(cast(sum(score)*100/nullif(sum(sum(score)) over(partition by 1),0) as numeric(18,2)) as varchar(50))+'%' as 班級總分占比
from stu
group by class

 

2、patition by 字段   根據該字段匯總

 select * from stu 

 

select
class,
name,
sum(score) 個人總分,
sum(sum(score)) over(partition by name) 個人總分,
sum(sum(score)) over(partition by class) 班級總分,
sum(sum(score)) over(partition by 1) 年級總分
from stu
group by class,name