Delete Duplicate emails 5-10-22

link - https://www.codingninjas.com/codestudio/problems/delete-duplicate-emails_2111947?topList=top-100-sql-problems&leftPanelTab=0

Problem Statement

 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  |
+----+------------------+
Note:

  Your output is the whole Person table after executing your sql. Use delete statement.


----------------- solution ------------------------------

delete from person where id in (select p1.id from person p1
        join person p2 on
        p1.id > p2.id and p1.email=p2.email);
select * from person;