Leetcode Database:delete Duplicate Emails

Write a SQL query to delete all duplicate e-mail entries in a table named Person , keeping unique emails based on its smallest Id.

+----+------------------+| Id | Email            |+----+------------------+| 1  | [Email protected] | | 2  | [email protected]  | | 3  | [Email protected] |+----+------------------+id is the primary key, column for this table.

For example, after running your query, the above Person table should has the following rows:

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

# Write your MySQL query statement belowdelete from the person where Id not in (the Select ID from (    select ID,    if (STRCMP (@ Prev, email) =0, false, True) as Diff,    @prev: = email    from     (SELECT * FROM person P2 order by Email, Id ASC) x,< c5/> (select @prev: = ') y) t where t.diff=true)

　　

Leetcode Database:delete Duplicate Emails