leetcode数据库sql之Delete Duplicate Emails

leetcode原文引用：

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  | [e-mail] || 2  | [e-mail]  || 3  | [e-mail] |+----+------------------+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  | [e-mail] || 2  | [e-mail]  |+----+------------------+

我的sql语句：

DELETE FROM Person WHERE    id NOT IN (SELECT         id    FROM        (SELECT             MIN(id) AS id        FROM            Person        GROUP BY email) AS a);