leetcode:182. duplicate emails

题目描述

Write a SQL query to find all duplicate emails in a table named Person.

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+----+---------+
| Id | Email   |
+----+---------+
| 1  | [email protected] |
| 2  | [email protected] |
| 3  | [email protected] |
+----+---------+

For example, your query should return the following for the above table:

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+---------+
| Email   |
+---------+
| [email protected] |
+---------+

这题考查having语句的用法

代码实现

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select email 
from person 
group by email
having count(email) > 1;