# 196. Delete Duplicate Emails

**<font color=red>难度: Easy</font>**

## 刷题内容

> 原题连接

* https://leetcode.com/problems/delete-duplicate-emails/

> 内容描述

```
Write a SQL query to delete all duplicate email entries in a table named Person, keeping only unique emails based on its smallest Id.

+----+------------------+
| Id | Email            |
+----+------------------+
| 1  | john@example.com |
| 2  | bob@example.com  |
| 3  | john@example.com |
+----+------------------+
Id is the primary key column for this table.
For example, after running your query, the above Person table should have the following rows:

+----+------------------+
| Id | Email            |
+----+------------------+
| 1  | john@example.com |
| 2  | bob@example.com  |
+----+------------------+
Note:

Your output is the whole Person table after executing your sql. Use delete statement.
```

## 解题方案

> 思路 1


```sql
delete p1 from Person p1, Person p2 where p1.Email = p2.Email and p1.Id > p2.Id
```










































