delete dup email

leetcode

https://leetcode.com/problems/delete-duplicate-emails/

DELETE P2 FROM Person (as) P1, Person (as) P2 WHERE P1.Email = P2.Email AND P1.Id < P2.Id;

sql FROM Person (as) P1, Person (as) P2 is an implicit join same as an inner join; as can be ignored

REF:

• https://github.com/int32bit/leetcode/tree/master/database/DeleteDuplicateEmails
• http://yanhuqing666.github.io/leet-code-database-easy
• http://stackoverflow.com/questions/5118562/inner-join-vs-multiple-table-names-in-from
• group_by is precedent than select, so the result is group_by email first and then select the min ID from each group