【MySQL】【leetcode】 Delete Duplicate Emails解题报告

题目

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 [e-mail] 2 [e-mail] 3 [e-mail]

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 [e-mail] 2 [e-mail]

题目来源：https://leetcode.com/problems/delete-duplicate-emails/

代码

Email重复的话，保留ID最小的那条记录，其余的删除。

#方法一：# Write your MySQL query statement belowdelete from Personwhere Id not in (  select * from (    select MIN(Id) from Person group by Email  ) as tb);#方法二：# Write your MySQL query statement belowdelete p1 from  Person as p1, Person as p2where p1.Email = p2.Email and p1.Id > p2.Id;