over的功能：

一、

with Ta as

(

select 1 as Fa, 'a' as Fb

union all

select 2 as Fa, 'b' as Fb

union all

select 3 as Fa, 'c' as Fb

union all

select 4 as Fa, 'd' as Fb

union all

select 5 as Fa, 'e' as Fb

)

select FB ,1.*Fa/(select sum(Fa) from Ta)

from Ta

with Ta as

(

select 1 as Fa, 'a' as Fb

union all

select 2 as Fa, 'b' as Fb

union all

select 3 as Fa, 'c' as Fb

union all

select 4 as Fa, 'd' as Fb

union all

select 5 as Fa, 'e' as Fb

)

select FB ,1.*Fa/sum(Fa) over()

from Ta

二、配合row_number()函数使用

SELECT CONTRACT_BH,CONTRACT_ID ,ROW_NUMBER()OVER(ORDER BY JKR_CUST_ID) AS ROWNUMBER

FROM TCOMMCREDIT

WHERE ROWNUMBER <=  10

三、推广 row_number() 到rank

USE a;

GO

SELECT A.CONTRACT_BH, A.CONTRACT_ID, B.CUST_NAME, RANK() OVER (PARTITION BY A.JKR_CUST_ID order by A.CONTRACT_ID) as RANK

FROM TCOMMCREDIT A ,TENTCUSTINFO B

WHERE A.JKR_CUST_ID = B.CUST_ID

GO