Question

我想从union列中获取最后一个请求日期。我有这段代码显示最后一个请求日期：

;with cte 
as
(
    select
        [Date], [Badge id], Name, Reason, [Item1] item, 
        row_number() over (partition by [Badge id], [Item1] order by getdate()) rn
    from tbl_Request2
    where [Item1] Is Not null

    union

    select
        [Date], [Badge id], Name, Reason,[Item2] item,
        row_number() over (partition by [Badge id], [Item2] order by getdate()) rn
    from tbl_Request2 where [Item2] is not null union
)
Select
    T.[Badge ID], T.Name, T.Item, T.Reason, T. [Date] as [Current Request],
    ISNULL((Select top 1 [Date]
            from CTE
            where
                CTE.[Badge Id]=T.[Badge Id] and 
                CTE.[Item] = T.item and 
                CTE. [Date] < T. [Date]),T. [Date]) as [Last Requested] 
From CTE T 
order by [Badge ID]

它会显示最后一条记录，但不会显示预期的记录。它显示，例如：

ID 01 001 request item1 on 12/05/2014那么

ID 001再次请求2014年1月13日的第1项;它显示最后请求的12/05/2014;然后

ID 001在14/05/2014再次请求Item1;它显示最后请求的12/05/2014; - ＆GT;这是错误   我希望它显示最后一个请求13/05/2014

预期表格：

 ID   |  Items     |  Date        | Last Request Date
 001  |  Item1     |  12/05/2014  | 12/05/2014 --> lets say this is the first request of ID001
 002  |  Item2     |  25/04/2014  | 20/05/2014      
 001  |  Item1     |  13/05/2014  | 12/05/2014 --> It display the date of first requested     
 001  |  Item1     |  14/05/2014  | 13/05/2014 --> display the second request date

您对此错误有任何建议吗？很抱歉再次发布。我昨天已经问了这个问题，但它仍有一些错误。

谢谢你的进步......

Answer 1

这有点令人尴尬。我问了一个问题并自己回答。我只是意识到代码中缺少的东西。我只需删除前1并在我的代码上添加max（date）。对不起，问一些我错了。

;with cte 
as
(
    select
        [Date], [Badge id], Name, Reason, [Item1] item, 
        row_number() over (partition by [Badge id], [Item1] order by getdate()) rn
    from tbl_Request2
    where [Item1] Is Not null

    union

    select
        [Date], [Badge id], Name, Reason,[Item2] item,
        row_number() over (partition by [Badge id], [Item2] order by getdate()) rn
    from tbl_Request2 where [Item2] is not null union
)
Select
    T.[Badge ID], T.Name, T.Item, T.Reason, T. [Date] as [Current Request],
    ISNULL((Select max[Date] as [date]
            from CTE
            where
                CTE.[Badge Id]=T.[Badge Id] and 
                CTE.[Item] = T.item and 
                CTE. [Date] < T. [Date]),T. [Date]) as [Last Requested] 
From CTE T 
order by [Badge ID]

如何将最后一个请求日期视为请求历史记录

1 个答案: