LeeCode(Database)-Duplicate Emails
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 above table:
+---------+
| Email |
+---------+
| a@b.com |
+---------+
# Write your MySQL query statement below
select Email from Person group by Email having COUNT(Email)>1
LeeCode(Database)-Duplicate Emails的更多相关文章
- [LeetCode] Delete Duplicate Emails 删除重复邮箱
Write a SQL query to delete all duplicate email entries in a table named Person, keeping only unique ...
- [LeetCode] Duplicate Emails 重复的邮箱
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
- Leetcode 182. Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
- [SQL]LeetCode182. 查找重复的电子邮箱 | Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
- LeetCode DB: Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
- 【SQL】182. Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
- LeetCode - Duplicate Emails
Description:Write a SQL query to find all duplicate emails in a table named Person. 找出表中重复的Email. # ...
- 182. Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
- Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Emai ...
随机推荐
- easyhadoop初识以及各种问题
版本:easyhadoop 1.2.1,操作系统:Centos 6.4: 首先,我要说的是要用对版本,这点很重要.我使用ubuntu12.04 64bit 的虚拟机是不行的,安装直接报错.所以就下载了 ...
- linux使用共享内存通信的进程同步退出问题
两个甚至多个进程使用共享内存(shm)通信,总遇到同步问题.这里的“同步问题”不是说进程读写同步问题,这个用信号量就好了.这里的同步问题说的是同步退出问题,到底谁先退出,怎么知道对方退出了.举个例子: ...
- 第六百二十一天 how can I 坚持
好歹都是一些集成的框架,也懒得去深入研究了,微信小程序,今天体验了一个,虽然内心非常相信张小龙,但是还是不太看好,但是感觉确实需要一种方式去简化应用程序的开发,今天把没用的app都删了,太耽误时间了, ...
- Js操作Select
jquery操作select(取值,设置选中) 每一次操作select的时候,总是要出来翻一下资料,不如自己总结一下,以后就翻这里了. 比如<select class="selecto ...
- java与.net比较学习系列(7) 属性
文章摘自:http://www.cnblogs.com/mcgrady/p/3411405.html 说起属性,实际上java中没有属性这个概念,只有字段和方法,但是可以通过私有字段和声明get,se ...
- BZOJ 2733 HNOI 2012 永无乡 平衡树启示式合并
题目大意:有一些岛屿,一開始由一些无向边连接. 后来也有不断的无向边增加,每个岛屿有个一独一无二的重要度,问随意时刻的与一个岛屿联通的全部岛中重要度第k大的岛的编号是什么. 思路:首先连通性一定要用并 ...
- mac下显示隐藏文件
一.在终端中 ls -a就可以查看隐藏文件. 显示和隐藏的命令例如以下: 显示:defaults write com.apple.finder AppleShowAllFiles -bool true ...
- HDU4496_D-City(并查集删边/逆向)
D-City Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65535/65535 K (Java/Others) Total Sub ...
- EffectiveC#17--装箱和拆箱的最小化
1.如下这段代码会经历装箱和拆箱.例如25会先装箱成object后传递给writeline方法(一次拷贝),在方法内部又 经历拆箱成int(第二次拷贝)后然后调用tostring(). Console ...
- PHP session 跨子域问题总结
Session主要分两部分: 一个是Session数据,该数据默认情况下是存放在服务器的tmp文件下的,是以文件形式存在 另一个是标志着Session数据的Session Id,Session ID, ...