Solution


Approach: Using DELETE and WHERE clause [Accepted]

Algorithm

By joining this table with itself on the Email column, we can get the following code.

SELECT p1.*
FROM Person p1,
    Person p2
WHERE
    p1.Email = p2.Email
;

Then we need to find the bigger id having same email address with other records. So we can add a new condition to the WHERE clause like this.

SELECT p1.*
FROM Person p1,
    Person p2
WHERE
    p1.Email = p2.Email AND p1.Id > p2.Id
;

As we already get the records to be deleted, we can alter this statement to DELETE in the end.

MySQL

DELETE p1 FROM Person p1,
    Person p2
WHERE
    p1.Email = p2.Email AND p1.Id > p2.Id