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 |…

题目标签: 题目给了我们一个 email 的表格,让我们删除重复的. 建立Person p1,Person p2,当email 相同时,而且 p1 id 要大于 p2 id 时候,删除这一行. Java Solution: Runtime:  869 ms, faster than 33 % Memory Usage: N/A 完成日期:06/01/2019 关键点:p1.Id > p2.Id # Write your MySQL query statement below DELETE p1…

Discription:Write a SQL query to delete all duplicate email entries in a table named Person, keeping only unique emails based on its smallest Id. 删除重复的Email地址,保留Id最小的那个. 使用自身连接循环即可. # Write your MySQL query statement below delete p1 from Person p1, P…

题目标签: 题目给了我们一个 email 的table,让我们找到重复的 email. 可以建立 Person a, Person b, 找到两个表格中,emai 相等 但是 id 不同的 email, 然后利用DISTINCT 返回,因为两个表格中,会找到两个 重复的email. Java Solution: Runtime:  224 ms, faster than 40 % Memory Usage: N/A 完成日期:06/01/2019 关键点:用DISTINCT # Write yo…

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 |…

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 |…

Given an array of integers, find out whether there are two distinct indices i and j in the array such that the difference between nums[i] and nums[j] is at most t and the difference between i and j is at most k. 这道题跟之前两道Contains Duplicate 包含重复值和Conta…

Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Email | +----+---------+ | 1 | a@b.com | | 2 | c@d.com | | 3 | a@b.com | +----+---------+ For example, your query should return the following for the abov…

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 |…

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 |…