> For the complete documentation index, see [llms.txt](https://zqt0.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zqt0.gitbook.io/leetcode/sql/182.duplicate-emails.md).

# 182.(Easy)查找重复的电子邮箱

编写一个 SQL 查询，查找 Person 表中所有重复的电子邮箱。

示例：

```
+----+---------+
| Id | Email   |
+----+---------+
| 1  | a@b.com |
| 2  | c@d.com |
| 3  | a@b.com |
+----+---------+
```

根据以上输入，你的查询应返回以下结果：

```
+---------+
| Email   |
+---------+
| a@b.com |
+---------+
说明：所有电子邮箱都是小写字母。
```

来源：力扣（LeetCode）

链接：<https://leetcode-cn.com/problems/duplicate-emails>

著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

## Solution

```sql
select Email
from Person
group by 1
having count(1)>1
```