Question

如何使用内部联接来摆脱我不想要的欺骗？我正在研究的表格如下：

ID  Edited_date  Status
------------------------
1   1/1/2015     A    
1   1/1/2016     B    
1   2/1/2016     C    
2   1/1/2017     D     
2   3/1/2017     B     
3   1/1/2016     C    
3   4/1/2017     B    
3   1/1/2014     D

但是，我只想从最近的edited_date

获得每笔贷款的状态

ID  Edited_date  Status
------------------------
1   2/1/2016     C
2   3/1/2017     B 
3   4/1/2017     B

Answer 1

select * from [table] t1
inner join 
(
select ID, max(Edited_date) maxDt
from [Table]
group by ID
) t2
on t1.ID = t2.ID
and t1.Edited_date = t2.maxDt;

Answer 2

仅供选择：

SELECT * 
FROM 
(
SELECT *, ROW_NUMBER()OVER(PARTITION BY ID ORDER BY Edited_date desc) as Indicator
FROM TABLE_NAME
) as ABC
WHERE ABC.Indicator = 1

删除：

WITH ABC
AS
(
SELECT *, ROW_NUMBER()OVER(PARTITION BY ID ORDER BY Edited_date desc) as Indicator
FROM TABLE_NAME
)
DELETE FROM ABC
WHERE ABC.Indicator != 1

Answer 3

使用id分区的row_number()获取最新的edited_date

select id, edited_date, status
from (
  select *
    , rn = row_number() over (partition by id order by edited_date desc)
  from t
    ) as s
where rn = 1

top with ties版本：

select top 1 with ties
    id
  , edited_date
  , status
from t
order by row_number() over (partition by id order by edited_date desc)

Answer 4

Begin Transaction

Create table #temp (Id int, Edited_date date, Status char(2))

Insert into #temp
Values
('1','1/1/2015','A'),   
('1','1/1/2016','B'),  
('1','2/1/2016','C'),    
('2','1/1/2017','D'),      
('2','3/1/2017','B'),      
('3','1/1/2016','C'),     
('3','4/1/2017','B'),     
('3','1/1/2014','D')

Create table #temp2 (Id int, Edited_date date, Status char(2))

Insert into #temp2
Values
('1','2/1/2016','C'),
('2','3/1/2017','B'), 
('3','4/1/2017','B')

/** emphasis on the below **/

;with cte as (
Select max(Edited_date) as Edited_date, Status From #temp Group By Status
union all
Select max(Edited_date) as Edited_date, Status From #temp2 Group By Status
)

Select Status, max(Edited_date) as Recent_Edited_date From cte Group By Status

/** End of Emphasis **/

Drop table #temp
Drop table #temp2

Rollback

--- Result ---

Status| Recent_Edited_date

A|  2015-01-01    
B|  2017-04-01    
C|  2016-02-01    
D|  2017-01-01

如何做一个内部联接摆脱欺骗

4 个答案: