Question

我有一个表，其中有多个列需要删除重复数据，但是我需要为每行保留现有的主键。显然，当运行没有主键列（Source_ID）的SELECT DISTINCT ....时，排除主键列时会提供所需的结果。

所以我如何获取不同的行并维护现有的主键数据。

Source table before de-dupe

Source_ID   Title   First_Name  Last_Name   Organisation
1000013     Mr      James       Caine       Company1 
1000014     Ms      Judith      Jason       Company2
1000015     Mr      James       Caine       Company1 


table after de-dupe

Source_ID   Title   First_Name  Last_Name   Organisation
1000013     Mr      James       Caine       Company1 
1000014     Ms      Judith      Jason       Company2

Answer 1

使用ROW_NUMBER()如下：

SELECT Source_ID, Title, First_Name, Last_Name, Organisation
FROM
    (SELECT *,ROW_NUMBER() OVER(Partition by Title, First_Name, Last_Name, Organisation Order by Source_ID) as rn
    FROM YourTable) as tblMain
WHERE rn = 1

Answer 2

也许您只想聚合：

select max(source_id) as source_id,
       Title, First_Name, Last_Name, Organisation
from t
group by Title, First_Name, Last_Name, Organisation;

Answer 3

您可以使用“从此处查找重复值”

;WITH cte AS 
(SELECT Source_ID, Title, First_Name, Last_Name, Organisation,
rn=ROW_NUMBER() OVER(Partition by Title, First_Name, Last_Name, Organisation Order by Source_ID 
FROM YourTable)
SELECT * 
FROM WHERE rn > 1

Detect duplicate items in recursive CTE

SQL Server-删除重复的行并维护现有的主键

3 个答案: