Question

我正在尝试加入表变量表和另一个表。

@ProcessTbl      OrderDetail
Order            ID
Status           Order   
Approved         DateTime
Domain           Status

OrderDetail表有多列用于相同的订单。例如

ID  Order DateTime   Status
  1     1   11-17-10   Recived
  2     1   11-18-10   Processing
  3     1   11-19-10   shipped

所以我想要联接做的是从@processtbl获取订单号（表变量）并且对于max（id），在这种情况下获取日期时间最大id为3

所以我的结果应该是

order  status    approved  domain    datetime
 1     shipped   true      finance   11-19-10




  SELECT   t.order
            ,[od.DateTime] 
            ,t.Status
            ,t.Domain
        ,t.Approved     
    FROM @ProcessTable t
    JOIN OrderDetail od ON od.order= t.order
    WHERE od.ID = (SELECT MAX(id) FROM orderdetail WHERE od.order = t.order ) 
    ORDER BY od.[DateTime], Approved ASC

但是我仍然会获得重复的记录，看起来它正在对两个表进行评分。我怎样才能获得不同的记录？

Answer 1

select p.order, od.status, p.approved, p.domain, od.datetime 
from @ProcessTable p
inner join (
    select Order, max(ID) as MaxID
    from OrderDetail 
    group by Order
) odm
inner join OrderDetail od on odm.Order = od.Order 
    and odm.MaxID = od.ID

Answer 2

想一想，你试过SELECT DISTINCT吗？

Answer 3

WHERE od.ID = (SELECT MAX(id) FROM orderdetail WHERE od.order = t.order )

od.order不引用子查询中的orderdetail表，而是引用外部的实例。

尝试类似：WHERE od.ID = (SELECT MAX(id) FROM orderdetail as od1 WHERE od1.order = t.order )

SQL JOIN WITH WHERE

3 个答案: