Question

我有共享IdString的记录历史记录（每次更新的多条记录都具有完全相同的日期时间）。

我想要一个查询来确定哪些记录是最新更新组的一部分。

此查询将显示一个具有最新更新日期的记录，但表示每个分区，我需要具有该最大日期的所有记录。

;with cte as(
select ROW_NUMBER() over (partition by IdString order by UpdateDate desc) as [rn], *
from MyTable
)
select  CASE WHEN (cte.rn = 1) THEN 0 ELSE 1 END [IsOld], *
from MyTable m
inner join cte on cte.RecordId= m.RecordId

请有人帮我找出合适的查询吗？

编辑：示例

(IsOld is the desired calculated value)

IsOld RecordId  IdString  UpdateDate
1         1     ABC 2011-06-16 
1         2     ABC 2012-05-30 
1         3     ABC 2008-12-31 
0         4     ABC 2012-06-08 
1         5     ABC 2011-01-16 
0         6     ABC 2012-06-08 
1         7     ABC 2012-06-07 
1         8     XYZ 2001-01-16
1         9     XYZ 2013-01-30
0         10    XYZ 2001-01-31
1         11    XYZ 2013-06-01
1         12    XYZ 2001-05-04
0         13    XYZ 2013-01-30

Answer 1

SELECT CASE WHEN updateDate = maxDate THEN 0 ELSE 1 END isOldRecord, RecordID, IDString, UpdateDate
FROM 
(
select  m.RecordID, m.IDString, m.updateDate, MAX(UpdateDate) OVER (PARTITION BY IDString) maxDate
    from MyTable m
) A

Answer 2

试试这个 -

;WITH cte AS(
    SELECT RANK() OVER(PARTITION BY IdString ORDER BY UpdateDate DESC) AS [row_num], *
    FROM   MyTable
)
SELECT CASE WHEN m.[row_num] = 1 THEN 0 ELSE 1 END isOld, *
from cte m

SQL Query查找最新的记录组

2 个答案: