LeetCode OJ 182 Duplicate Emails

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Question

[LeetCode 182] Write a SQL query to find all duplicate emails in a table named Person.

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

Submission

SQL
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select EmailCount.Email from
(select Email, count(Id) as ec from Person group by Email) as EmailCount
where EmailCount.ec > 1;