SQL Server - 查找表中的重复项

Question

我们得到了拥有将近1亿多行的大表。谁能帮如何在表中找到重复的数据，并且可以将其移动到压缩文件

表名：CustomerData
NumberofFields：10

最新一个应该留（这是由END_DATE标识提到NULL在记录）

关注

Answer 1

你只需要动到哪END_DATE不为空行？

在一个单独的事务：

INSERT INTO archive (column1, column2, ... column10) 
SELECT column1, column2, ..., column10 
FROM CustomerData 
WHERE END_DATE IS NOT NULL 

DELETE CustomerData 
WHERE END_DATE IS NOT NULL 

Answer 2

您是否试过这种解决方案？

--INSERT Archive (columns) 
SELECT ... 10 columns ... 
FROM CustomerData 
WHERE END_DATE IS NULL 

Answer 3

假设CustomerData表结构为： CustomerDAta（的cust_id，CUST_NAME，ADDRESS_ID，START_TIME，结束日期，.....，其他7列）;

并假设2个客户有SAme地址ID以获得重复。

插入到存档表： -

INSERT INTO archive (column1, column2, ... column10) 
SELECT cust_id, start_Date, ...,End_Date 
FROM CustomerData 
WHERE END_DATE IS NOT NULL 
AND Address_ID IN(
     SELECT Address_ID FROM 
      (
      SELECT Address(ID),count(Address_ID) 
      FROM customerDAta 
      GROUP BY Address_ID 
      HAVING count(Adddress_ID)>1 
      ) 
     )      
         ) 

要删除： - CustomerDAt表： -

DELETE CustomerData 
WHERE END_DATE IS NOT NULL 
    AND 
    Address_ID IN(
      SELECT Address_ID FROM 
      (
      SELECT Address(ID),count(Address_ID) 
      FROM customerDAta 
      GROUP BY Address_ID 
      HAVING count(Adddress_ID)>1 
      ) 
     ) 

内部子提取重复基于类似于同ADDRESS_ID列Oracle数据库提供的employees表中的DeptID列。