選擇3最新的順序爲每個客戶

Question

這裏是我的表CusOrder收集客戶訂單

OrderID  Cus_ID Product_ID NumberOrder  OrderDate 
    1  0000000001  9   1  6/5/2553 0:00:00 
    2  0000000001  10   1  6/5/2553 0:00:00 
    3  0000000004  9   2  13/4/2553 0:00:00 
    4  0000000004  9   1  17/3/2553 0:00:00 
    5  0000000002  9   1  22/1/2553 0:00:00 
    7  0000000005  9   1  16/12/2552 0:00:00 
    8  0000000003  9   3  13/12/2552 0:00:00 
    10  0000000001  9   2  19/11/2552 0:00:00 
    11  0000000003  9   2  10/11/2552 0:00:00 
    12  0000000002  9   1  23/11/2552 0:00:00 

，我需要選擇3最新的順序爲每一個客戶，我需要所有的客戶 所以它會顯示每個客戶和他的/她的3最新的順序 我怎麼能做到這一點

對不起我的英文不好

Answer 1

WITH Temp AS 
(
    SELECT *, (ROW_NUMBER() OVER (PARTITION BY Cus_ID ORDER BY OrderDate DESC)) AS Number 
    FROM CusOrder 
) 
SELECT * FROM Temp WHERE Number <= 3 

應該工作。沒有測試這個確切的數據庫結構，但類似的東西。

Answer 2

這CTE應該爲你工作：

;with cteTop3PerGroup as 
(
    select row_number() over(partition by Cus_ID order by OrderDate DESC) as RN 
      , * 
    from CusOrder 
) 
select * from cteTop3PerGroup 
where RN <= 3 

Answer 3

「Pure」SQL解決方案。

With Customers As (
    Select Cus_ID From test Group By Cus_ID 
    ), 
TopLastOrders as (
    Select o.Cus_ID, Max(OrderDate) as OrderDate 
    From test o Inner Join Customers c on c.Cus_ID = o.Cus_ID 
    Group By o.Cus_ID 
    ), 
TopSecondOrders as (
    Select o.Cus_ID, Max(OrderDate) as OrderDate 
    From test o Inner Join Customers c on c.Cus_ID = o.Cus_ID 
    Where Not Exists (Select 1 From TopLastOrders Where Cus_ID=o.Cus_ID And OrderDate=o.OrderDate) 
    Group By o.Cus_ID 
    ), 
TopThirdOrders as (
    Select o.Cus_ID, Max(OrderDate) as OrderDate 
    From test o Inner Join Customers c on c.Cus_ID = o.Cus_ID 
    Where Not Exists (Select 1 From TopLastOrders Where Cus_ID=o.Cus_ID And OrderDate=o.OrderDate) 
     And Not Exists (Select 1 From TopSecondOrders Where Cus_ID=o.Cus_ID And OrderDate=o.OrderDate) 
    Group By o.Cus_ID 
    )
 

Select c.Cus_ID, t1.OrderDate, t2.OrderDate, t3.OrderDate From Customers c
 Left Outer Join TopLastOrders t1 on t1.Cus_ID = c.Cus_ID Left Outer Join TopLastOrders t2 on t2.Cus_ID = c.Cus_ID Left Outer Join TopLastOrders t3 on t3.Cus_ID = c.Cus_ID
 

Order By c.Cus_ID 

我不知道你需要什麼輸出，但這個應該不難。