关于SQL的over partition by 开窗语句在分页和统计中的使用总

标签：custom   with   一个   tiny   inf   avg   efault   default   desc   

CREATE TABLE OrderInfo(
ID INT IDENTITY(1,1) PRIMARY KEY,
CustomerID INT NULL,
TotalMoney DECIMAL(18,2) NULL,
OrderStatus TINYINT NULL DEFAULT 0,
CreateTime DATETIME DEFAULT GETDATE() NOT NULL
)

INSERT INTO OrderInfo
(
CustomerID,
TotalMoney,
OrderStatus,
CreateTime
)
SELECT 1,100,1,‘2015-03-21‘ UNION ALL
SELECT 2,50,1,‘2015-03-22‘ UNION ALL
SELECT 1,300,1,‘2015-03-23‘ UNION ALL
SELECT 3,1000,3,‘2015-03-24‘ UNION ALL
SELECT 2,20,1,‘2015-03-24‘ UNION ALL
SELECT 5,50,4,‘2015-03-20‘ UNION ALL
SELECT 8,600,2,‘2015-03-21‘ UNION ALL
SELECT 6,80,1,‘2015-03-22‘ UNION ALL
SELECT 2,70,1,‘2015-03-23‘ UNION ALL
SELECT 1,40,0,‘2015-03-23‘ UNION ALL
SELECT 9,20,1,‘2015-03-20‘ UNION ALL
SELECT 10,100,1,‘2015-03-21‘ UNION ALL
SELECT 6,99,1,‘2015-03-24‘ UNION ALL
SELECT 4,78,2,‘2015-03-25‘ UNION ALL
SELECT 2,100,1,‘2015-03-24‘

/*
找出每个顾客第一次下单的时间及金额
*/
with cte as(
select *,ROW_NUMBER() over(partition by customerid order by createtime) rm from OrderInfo
)
select * from cte where rm=1 --select CustomerID,min(CreateTime) from OrderInfo group by CustomerID

/*
找出每个顾客金额最大的订单金额
*/
with cte as(
select *,ROW_NUMBER() over(partition by customerid order by totalmoney desc) rm from OrderInfo
)
select * from cte where rm=1 ---select CustomerID,max(TotalMoney) from OrderInfo group by CustomerID

/*
统计每一个客户最近下的订单是第几次下的订单
*/
with cte as
(
select *,ROW_NUMBER() over(partition by customerid order by createtime) rm from OrderInfo
)select CustomerID,max(rm) from cte
group by CustomerID ---select CustomerID,count(CustomerID) from OrderInfo group by CustomerID

/*
统计所有客户第3次下单订单信息
*/
;with cte as(
select *,ROW_NUMBER() over(partition by customerid order by createtime) rm from OrderInfo
)
select * from cte where rm=3

/*
统计每一个客户所有订单金额的平均值
*/
select *,avg(TotalMoney) over(partition by customerid) rm from OrderInfo

/*
在使用over等开窗函数时，over里头的分组及排序的执行晚于“where，group by，order by”的执行。
*/
SELECT CustomerID,CreateTime,ROW_NUMBER() OVER (PARTITION BY customerID ORDER BY CreateTime) AS num
FROM OrderInfo
WHERE CustomerID>2

关于SQL的over partition by 开窗语句在分页和统计中的使用总

标签：custom   with   一个   tiny   inf   avg   efault   default   desc   

原文地址：http://www.cnblogs.com/coce/p/7225779.html