SQL Server - 查找表中的重複項

Question

我們得到了擁有將近1億多行的大表。誰能幫如何在表中找到重複的數據，並且可以將其移動到壓縮文件

表名：CustomerData
NumberofFields：10

最新一個應該留（這是由END_DATE標識提到NULL在記錄）

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Answer 1

你只需要動到哪END_DATE不爲空行？

在一個單獨的事務：

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

您是否試過這種解決方案？

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

Answer 3

假設CustomerData表結構爲： CustomerDAta（的cust_id，CUST_NAME，ADDRESS_ID，START_TIME，結束日期，.....，其他7列）;

並假設2個客戶有SAme地址ID以獲得重複。

插入到存檔表： -

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 
      ) 
     )      
         ) 

要刪除： - 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 
      ) 
     ) 

內部子提取重複基於類似於同ADDRESS_ID列Oracle數據庫提供的employees表中的DeptID列。