获取每个行号的最后一条记录

Question

你有这样的书面查询：

select Customerid,orderDate, OrderNumber,
       DENSE_RANK() OVER (PARTITION BY Customerid ORDER BY orderDate) "rank"
from [order]

，这会产生结果：

在这里，我想仅检索每个客户的最新购买：

1   2014-04-09 00:00:00.000 543141  6
2   2014-03-04 00:00:00.000 543056  4
3   2014-01-28 00:00:00.000 542986  7

如何使用sql查询实现此目的

Answer 1

使用子查询：

select o.*
from (select Customerid,orderDate, OrderNumber,
             DENSE_RANK() OVER (PARTITION BY Customerid ORDER BY orderDate DESC) as seqnum
      from [order] o
     ) o
where seqnum = 1;