Delete Duplicate Records

Write a SQL query to delete all duplicate email entries in a table, keeping only 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 have the following rows:

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

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

Explanation:
- Join the table on itself by the Email
- From this results filter the records that have p1.Id>p2.ID

Another approach:

Delete 
FROM Person 
WHERE Id not in ( Select A.Id From(Select min(Id) as Id from Person GROUP BY Email) A )

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