[LeetCode]--196. Delete Duplicate Emails

The Example

Solution

Solution1

DELETE p FROM Person p, Person q WHERE p.Id>q.Id AND q.Email=p.Email

Solution2

DELETE FROM Person WHERE Id NOT IN ( SELECT A.Id FROM (SELECT Min(Id) as Id FROM Person GROUP BY Email) A )

Another Clear Form:

DELETE FROM Person WHERE Id NOT IN ( SELECT * FROM ( SELECT Min(Id) FROM Person GROUP BY Email ) Tmp )

Reference

https://discuss.leetcode.com/topic/11698/a-simple-ac-solutionhttps://discuss.leetcode.com/topic/15672/solution-in-a-single-query-without-any-conflicts