leetcode - 182. 查找重复的电子邮箱

题目:

编写一个 SQL 查询,查找 Person 表中所有重复的电子邮箱。

示例:

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+----+---------+
| 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:

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+---------+
| Email |
+---------+
| a@b.com |
+---------+

说明:所有电子邮箱都是小写字母。

解答:

  • SQL
    1
    select Email from Person where Id in (select ID from Person group by Email having count(Email) >= 2)