Sql Server 开窗函数Over()的使用实例详解

declare @t table(
ProductID int,
ProductName varchar(20),
ProductType varchar(20),
Price int)
insert @t
select 1,'name1','P1',3 union all
select 2,'name2','P1',5 union all
select 3,'name3','P2',4 union all
select 4,'name4','P2',4

select t1.* from @t t1
 join (select ProductType, max(Price) Price from @t group by ProductType) t2 
 on t1.ProductType = t2.ProductType
 where t1.Price = t2.Price
 order by ProductType

 ;with cte as(select *, max(Price) over(partition by (ProductType)) MaxPrice from @t)
select ProductID,ProductName,ProductType,Price from cte where Price = MaxPrice
 order by ProductType

;WITH OrderInfo AS
(
 SELECT ROW_NUMBER() OVER(PARTITION BY EmployeeID ORDER BY OrderDate) AS Number,
 OrderID,CustomerID, EmployeeID,OrderDate FROM Orders (NOLOCK) 
)
SELECT Number,OrderID,CustomerID, EmployeeID ,OrderDate
From OrderInfo WHERE Number BETWEEN 0 AND 10

 WITH OrderInfo AS
(
SELECT COUNT(OrderID) OVER(PARTITION BY EmployeeID) AS TotalCount,OrderID,CustomerID, EmployeeID,OrderDate FROM Orders (NOLOCK)
)
SELECT OrderID,CustomerID, EmployeeID ,OrderDate,TotalCount From OrderInfo ORDER BY EmployeeID

 WITH OrderInfo AS
 (
 SELECT COUNT(OrderID) OVER() AS Count,OrderID,CustomerID, EmployeeID,OrderDate FROM Orders (NOLOCK)
 )