SQL更新：通过在@之前添加+ ID对电子邮件地址进行重复数据删除>

Question

我正在尝试在mySQL中更新客户表，其中包含重复的电子邮件地址和唯一的custom_ID。我想通过在@符号前添加'+'和customer_ID来更改重复的电子邮件地址，但仅适用于非唯一电子邮件地址。

UPDATE clients SET email = REPLACE(email,'@', CONCAT('+',custom_ID,'@'))

INPUT
+-----------+-------------------------+
| custom_ID | email                   |
+-----------+-------------------------+
|  1001     | [email protected]     |
|  1002     |    [email protected]    |
|  1007     |    [email protected]    |
|  1012     |        [email protected]     |
|  1020     |       [email protected]    |
|  1021     |        [email protected]     |
|  1023     |    [email protected]    |
|  1024     |       [email protected]    |
+-----------+-------------------------+

 OUTPUT
+-----------+----------------------------+
| custom_ID | email                      |
+-----------+----------------------------+
|  1001     |   [email protected]      |
|  1002     |      [email protected]     |
|  1007     | [email protected]     |
|  1012     |          [email protected]      |
|  1020     |         [email protected]     |
|  1021     |     [email protected]      |
|  1023     | [email protected]     |
|  1024     |         [email protected]     |
+-----------+----------------------------+

我正在尝试在mySQL中更新客户表，其中包含重复的电子邮件地址和唯一的custom_ID。我想通过在@ ...

Answer 1