The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000…

The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000…

The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000…

The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 85000…

SQL 架构 Create table If Not Exists Employee (Id ), Salary int, DepartmentId int) Create table If Not Exists Department (Id )) Truncate table Employee insert into Employee (Id, Name, Salary, DepartmentId) values (') insert into Employee (Id, Name, Sala…

The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000…

Employee表存储员工姓名.员工所在公寓.员工工资 Department表存储公寓id 评选出各个公寓的工资前三名的员工. 遇到的问题如下: limit,in等语句不能用在嵌套select语句中,多封装一层就可以了 select子句如何访问外部的关系表,虽然可以直接访问外面第一层的,但是无法访问外面第二层的 select dep.name as Department, who.name as Employee, who.salary as Salary from department as…

问题描述 解决方案 select b.name Department,a.name Employee,a.salary Salary from Employee a,Department b where a.departmentid=b.id and (select count(distinct salary) from Employee where departmentid=a.departmentid and salary>a.salary )<3 order by departmenti…

The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000…

[LeetCode]692. Top K Frequent Words 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/top-k-frequent-words/description/ 题目描述: Given a non-empty list of words, return the k most frequent elements. Your answer should be sorted by frequency f…

题目地址:https://leetcode.com/problems/top-k-frequent-elements/ 从一个数组中求解出现次数最多的k个元素,本质是top k问题,用堆排序解决. 关于堆排序,其时间复杂度在最好和最坏的场景下都是O(nlogn). 一开始想定义一个结构体,包含元素和元素个数两个成员,后直接用pair存储即可. 解题思路: 1. 分别统计每个数字的个数,建立数字和个数的映射,用pair存储,first=数字个数,second=数字,然后存入集合. 2. 以不同数字…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 解题方法 解题方法 字典 优先级队列 日期 题目地址:https://leetcode.com/problems/top-k-frequent-elements/description/ 题目描述 Given a non-empty array of integers, return the k most frequent elements. For example,…

Given a non-empty array of integers, return the k most frequent elements. For example,Given [1,1,1,2,2,3] and k = 2, return [1,2]. 其实最简单的就是想到就是用一个小顶堆实现,如果堆中元素个数小于K,则插入元素,如果大于K,则和堆顶比较,如果大于堆顶,则弹出堆顶,插入新元素. 自己实现红黑树有点难,好在C++ STL容器中,map,set和priority_queue都…

LeetCode有10道SQL的题目,最近学习SQL语言,顺便刷题强化一下, 说实话刷完SQL学习指南这本书,不是很难,上面的例子 跟语法规则我都能理解透, 实际中来做一些比较难的业务逻辑题,却一下子很难想起如何利用SQL来描述 还是要多刷题开阔自己的思路,把学到手的语法加以练习 应用到实际中去 197. Rising Temperature Given a Weather table, write a SQL query to find all dates' Ids with higher t…

175. Combine Two Tables 使用外连接即可. # Write your MySQL query statement below select FirstName, LastName, City, State from Person left outer join Address on Person.PersonId = Address.PersonId; # Write your MySQL query statement below select p.FirstName,…

The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | S alary | DepartmentId | +----+-------+--------+--------------+ | 1 | J…

题目链接:https://leetcode.com/problems/nth-highest-salary/description/ 题意:查询出表中工资第N高的值 思路: 1.先按照工资从高到低排序(注意去重) select distinct Salary from Employee order by Salary desc 2.使用rownum给查询出的数据标注行号 select rownum ro, s.Salary from (select distinct Salary from Em…

175 Combine Two Tables 题目:左连接Person表和Address表. select FirstName,LastName,City,State from Person p left join Address a on p.PersonId=a.PersonId; 7个case耗时1001ms(注意耗时多次提交会不同,一般相差不大,偶尔也有相差大的)   --2015/1/11 176 Second Highest Salary 题目:写一条sql语句查询Employee …

The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Jo…

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 rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking number should be the next consecutive integer value. In other words, there should be no "holes" be…

Consecutive Numbers Write a SQL query to find all numbers that appear at least three times consecutively. +----+-----+ | Id | Num | +----+-----+ | 1 | 1 | | 2 | 1 | | 3 | 1 | | 4 | 2 | | 5 | 1 | | 6 | 2 | | 7 | 2 | +----+-----+ For example, given the…

X city built a new stadium, each day many people visit it and the stats are saved as these columns: id, date, people Please write a query to display the records which have 3 or more consecutive rows and the amount of people more than 100(inclusive).…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 477 Total Hamming Distance 44.10% Meidum 475 Heaters  30.20% Easy 474 Ones and Zeroes  34.90% Meidum 473 Matchsticks to Square  31.80% Medium 472 Concatenated Words 29.20% Hard…

请点击页面左上角 -> Fork me on Github 或直接访问本项目Github地址:LeetCode Solution by Swift    说明:题目中含有$符号则为付费题目. 如:[Swift]LeetCode156.二叉树的上下颠倒 $ Binary Tree Upside Down 请下拉滚动条查看最新 Weekly Contest!!! Swift LeetCode 目录 | Catalog 序        号 题名Title 难度     Difficulty  两数之…

LeetCode SQL题目 注意:Leetcode上的SQL编程题都提供了数据表的架构程序,只需要将它贴入本地数据库即可调试自己编写的程序 不管是MS-SQL Server还是MySQL都需要登陆才能使用,我没有使用SSMS 或Workbench,而是直接使用sqlcmd,解决登陆问题可以参考这个链接(http://www.cnblogs.com/skynothing/archive/2010/08/26/1809125.html)感谢这位博主的帮助. 181. Employees Earni…

All LeetCode Questions List(Part of Answers, still updating) 题目汇总及部分答案(持续更新中) Leetcode problems classified by company 题目按公司分类(Last updated: October 2, 2017) .   Top Interview Questions # Title Difficulty Acceptance 1 Two Sum Medium 17.70% 2 Add Two N…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 如果各位看官们,大神们发现了任何错误,或是代码无法通过OJ,或是有更好的解法,或是有任何疑问,意见和建议的话,请一定要在对应的帖子下面评论区留言告知博主啊(如果不方便注册博客园的话,可以下载下文提到的APP,在Feedback中给博主发邮件交流哈),同时也请大家踊跃地,大量地,盲目地提供各个题目的follow up一起讨论哈,多谢多谢,祝大家刷得愉快…

一.Department Top Three Salaries The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--…

题目从难到易记录.解题过程中,如果不太熟悉,可以将题目中的表自己手动录入到自己的数据库中,就方便学习,测试. 185. Department Top Three Salaries 要求就是查询出每个部门工资在前三的人.题意值得注意的一点就是,要求找出的是工资数前三的人,而不是工资最高的前三位.区别就是前者查询出来的人可能大于3,而后者最大只能为3. 最终答案: select b.Name Department,a.Name Employee,a.Salary from (select Name,…