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  | john@example.com |

| 2  | bob@example.com  |

| 3  | john@example.com |

+----+------------------+

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  | john@example.com |

| 2  | bob@example.com  |

+----+------------------+

# Write your MySQL query statement below

delete from Person where Id not in

(

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,

    (select @prev := '') y

) t where t.Diff=true

)