https://leetcode.com/problems/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 | [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 | [email protected] | | 2 | [email protected] | +----+------------------+
Note:
Your output is the whole Person table after executing your sql. Use deletestatement.
代码：
# Write your MySQL query statement below DELETE t1 FROM Person t1, Person t2 WHERE t1.Email = t2.Email AND t1.Id > t2.Id
FH