找到重複的電子郵件地址

Question

我需要在我們的數據庫中找到重複的電子郵件地址。我正在一張桌子上尋找這些信息。我有什麼到目前爲止

SELECT name.email, name.ID 

From Name 
Group BY Name.ID, Name.EMAIL 
Having Count(*) > 1 

我知道它錯了，但不知道如何給它適當寫。

Answer 1

刪除ID

SELECT name.email 
From Name 
Group BY Name.EMAIL 
Having Count(*) > 1 

，如果你想獲得的電子郵件的數量，

SELECT name.email, COUNT(*) totalEmailCount 
From Name 
Group BY Name.EMAIL 
Having Count(*) > 1 

Answer 2

在這裏你去：

SELECT name.email, COUNT(*) 
FROM 
    Name 
GROUP BY 
    Name.email 
HAVING 
    COUNT(*) > 1 

Answer 3

查詢將

SELECT name.email, COUNT(*) FROM Name 
GROUP BY Name.email HAVING COUNT(*) > 1 

您需要知道的是，如果您也按ID進行分組，計數將爲1，這就是爲什麼您的查詢不起作用。

如果您需要知道用戶的ID與複製，你可以做到這一點電子郵件：

select Name.ID, Name.Email from Name where Name.Email in (

SELECT name.email FROM Name 
    GROUP BY Name.email HAVING COUNT(*) > 1 
) 

Answer 4

select id,email from 
(select id,email,count(email) over (partion by email order by id) cnt from name) where cnt>1