Question

我知道MySQL有限制命令，但我不知道我应该在SQL Server 2008中使用什么命令？

我需要选择clientId和每次取件的最后一天，大多数客户都有多个取件（拾取表中有65 000 +条记录）。

select  P.ClientID,LastName+' '+FirsName as Name , Adress,p.PickupDate
from Pickup P,Clients C
where P.ClientID= C.ClientID
order by PickupDate desc limit 1


throwing error *Msg 102, Level 15, State 1, Line 4
Incorrect syntax near 'limit'.*
because **LIMIT** is not key word in SQL server

Answer 1

limit命令在sql server中是最高的

select top 1 P.ClientID
   ,LastName+' '+FirsName as Name 
   ,Adress
   ,p.PickupDate
from Pickup P
join Clients C on P.ClientID= C.ClientID
order by PickupDate desc

每张海报的澄清 - 这甚至不是一个顶级/限制问题。这是一个简单的分组声明。

select P.ClientID
   ,LastName+' '+FirsName as Name 
   ,Adress
   ,max(p.PickupDate)
from Pickup P
join Clients C on P.ClientID= C.ClientID
group by p.clientid, lastname + ' ' + firsname,adress

Answer 2

这通常是使用windowing functions完成的（2012年之前）：

;WITH Data
AS
    (
    SELECT P.ClientID
        , LastName + ' ' + FirsName as Name
        , Address
        , PickupDate
        , ROW_NUMBER() OVER(PARTITION BY P.ClientID ORDER BY PickupDate DESC)
            AS [Entry #]
    FROM Pickup P
    JOIN Clients C
        ON P.ClientID= C.ClientID
    )
SELECT *
FROM Data
WHERE [Entry #] = 1
ORDER BY PickupDate DESC

请参阅this blog post以获得对该技术的一些改进（以避免扫描不必要的行）。

Answer 3

试试这个

select P.ClientID, LastName+' '+FirsName as 'Name', Adress, max(p.PickupDate)
from Pickup P,Clients C
where P.ClientID= C.ClientID
GROUP BY P.ClientID, Adress, LastName+' '+FirsName
order by PickupDate desc

Fiddle

SQL Server TSQL相当于'MySQL Limit'？

3 个答案: