SQL Server 2005- OVER() partition

This will be useful for GridView pagination:

An aggregate functions can be added to any SELECT (even without a GROUP BY clause) by specifying an OVER() partition for each function.

This means that this code:

   1: select 

   2:     o.customerID, o.productID, o.orderDate, o.orderAmount, t.Total

   3: from 

   4:     Orders o

   5: inner join 

   6:    (

   7:     select customerID, sum(orderAmount) as Total from Orders group by customerID

   8:    ) 

   9:   t on t.customerID = o.customerID

can be replaced with:

   1: select customerID,  productID, orderDate, orderAmount, 

   2:       sum(orderAmount) OVER (Partition by CustomerID) as Total

   3: from Orders

Source