Delete Duplicate Emails---easy

删除Person表中重复的Email，只留下id最小的Email

Person表，主键是Id

+----+------------------+| Id | Email            |+----+------------------+| 1  | [e-mail] || 2  | [e-mail]  || 3  | [e-mail] |+----+------------------+

结果：

+----+------------------+| Id | Email            |+----+------------------+| 1  | [e-mail] || 2  | [e-mail]  |+----+------------------+

SQL语句：

delete a from Person as a,Person as b  where a.id>b.id and a.Email=b.Email;