Question

我有一个订单表，我希望按客户ID

获取最近的三个订单

customer    orderID     orderDate     
1           234          2018-01-01    
1           236          2017-02-01       
3           256          20157-03-01

我能够使用行号（）来识别表中每行的行号，但有没有办法按客户ID获取最近的三个订单？有些客户的订单少于3个，而其他客户订单超过10个，因此我无法按行号指定。

是否有人有其他选项的建议？

Answer 1

这是一个使用apply的有趣方法（假设你有一个customers表）：

select o.*
from customers c cross apply
     (select top 3 o.*
      from orders o
      where o.customerid = c.customerid
      order by orderdate desc
     ) o;

Answer 2

您可以使用partition by;

select customerid, orderid,orderdate from (
select t.customerid, t.orderid,t.orderdate
,row_number() over (partition by t.customerid order by t.orderDate desc) as mostRecently
from samplecustomers t)
Records where mostRecently < 4

Answer 3

试试这个：

SELECT * 
  FROM orders 
 WHERE customer = 1 
 ORDER BY orderDate ASC limit 3

这应该可以解决问题。

Answer 4

使用此查询：

SELECT result.customer
     , result.orderID
     , result.orderDate
 FROM
     (
     SELECT Temp.customer
          , Temp.orderID
          , Temp.orderDate
          , ROW_NUMBER() OVER(PARTITION BY Temp.customer 
                                  ORDER BY Temp.orderDate DESC) AS MR
      FROM YourTable AS Temp
     )  AS result
WHERE result.MR <= 3;

SQL查询以获取客户的三个最新记录

4 个答案: