leetcode.196. Delete Duplicate Emails

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 TMP.MIN_ID
FROM (SELECT MIN(ID) MIN_ID
FROM Person
GROUP BY Email) TMP);