SQL服務器：刪除重複的WHERE日期爲<日期

Question

我有這樣的表結構：

UNIQUE ID | TYPE | QUARTER | DATE 
1   | 1 |  JAN | 2/2/2222 
2   | 1 |  JAN | 4/2/2222 

如何刪除具有較舊日期重複記錄？

Answer 1

在MS SQL 2008：

with cte 
as 
(
    select *, row_number() over(partition by Quarter order by Date) RowNumber 
    from MyTable 
) 
delete cte 
where RowNumber > 1 

在任何SQL

delete 
from MyTable 
    where Date not in 
    (
     select Quarter, Min(DATE) 
     from MyTable 
     group by Quarter 
    ) 

假設沒有重複的日期字段。