My Solutions to Leetcode Database problems. 我的 Leetcode 数据.zip

## My solutions to Leetcode Database Problems I will put my solutions to [Leetcode Database Problems](https://leetcode.com/problemset/database/) in this repo. Please feel free to contact me if you have any questions with this repo:) email: [liuyubobobo@gmail.com](mailto:liuyubobobo@gmail.com) --- 大家好，欢迎大家来到我的 **Leetcode 数据库题解**代码仓。在这个代码仓中。如果对代码仓有任何问题，欢迎联系我：） **电子邮件**：[liuyubobobo@gmail.com](mailto:liuyubobobo@gmail.com) **知乎**: [刘宇波 http://www.zhihu.com/people/liuyubobobo](http://www.zhihu.com/people/liuyubobobo) **知乎专栏：**[是不是很酷 https://zhuanlan.zhihu.com/liuyubobobo](https://zhuanlan.zhihu.com/liuyubobobo) **个人公众号：是不是很酷**：）  **知识星球（免费）**  <br/> ## 其他相关代码仓 * [**《算法与数据结构》课程**](https://coding.imooc.com/class/71.html), 代码仓: [Play-with-Algorithms](https://github.com/liuyubobobo/Play-with-Algorithms) * [**《玩转算法面试》课程**](https://coding.imooc.com/class/82.html), 代码仓: [Play-with-Algorithm-Interview](https://github.com/liuyubobobo/Play-with-Algorithm-Interview) * [**《看得见的算法》课程**](https://coding.imooc.com/class/138.html), 代码仓: [Play-with-Algorithm-Visualization](https://github.com/liuyubobobo/Play-with-Algorithm-Visualization) * [**《玩转数据结构》课程**](https://coding.imooc.com/class/207.html), 代码仓: [Play-with-Data-Structures](https://github.com/liuyubobobo/Play-with-Data-Structures) * [**《玩转图论算法》课程**](https://coding.imooc.com/class/370.html), 代码仓: [Play-with-Graph-Algorithms](https://github.com/liuyubobobo/Play-with-Graph-Algorithms) * **Leetcode 算法题解代码仓**：[Play Leetcode](https://github.com/liuyubobobo/Play-Leetcode) （注：以C++实现为主） <br/> ## Problems | ID | Problem | Official<br/>Solution | MySQL | Comments | | --- | --- | :---: | :--: | :--- | | 175 | [Combine Two Tables](https://leetcode.com/problems/combine-two-tables/) | [solution](https://leetcode.com/problems/combine-two-tables/solution/) | [MySQL](0175-Combine-Two-Tables/) | | | 176 | [Second Highest Salary](https://leetcode.com/problems/second-highest-salary/) | [solution](https://leetcode.com/problems/second-highest-salary/solution/) | [MySQL](0176-Second-Highest-Salary/) | | | | | | | | | 181 | [Employees Earning More Than Their Managers](https://leetcode.com/problems/employees-earning-more-than-their-managers/) | [solution](https://leetcode.com/problems/employees-earning-more-than-their-managers/solution/) | [MySQL](0181-Employees-Earning-More-Than-Their-Managers/) | | | 182 | [Duplicate Emails](https://leetcode.com/problems/duplicate-emails/) | [solution](https://leetcode.com/problems/duplicate-emails/solution/) | [MySQL](0182-Duplicate-Emails/) | | | 183 | [Customers Who Never Order](https://leetcode.com/problems/customers-who-never-order/) | [solution](https://leetcode.com/problems/customers-who-never-order/solution/) | [MySQL](0183-Customers-Who-Never-Order/) | | | 184 | [Department Highest Salary](https://leetcode.com/problems/department-highest-salary/) | [solution](https://leetcode.com/problems/department-highest-salary/solution/) | [MySQL](0184-Department-Highest-Salary/) | | | | | | | | | 196 | [Delete Duplicate Emails](https://leetcode.com/problems/delete-duplicate-emails/) | [solution](https://leetcode.com/problems/delete-duplicate-emails/solution/) | [MySQL](0196-Delete-Duplicate-Emails/) | DELETE FROM SELF JOIN Table | | 197 | [Rising Temperature](https://leetcode.com/problems/rising-temperature/) | [solution](https://leetcode.com/problems/rising-temperature/solution/) | [MySQL](0197-Rising-Temperature/) | DATE_SUB or DATEDIFF | | | | | | | | 511 | [Game Play Analysis I](https://leetcode.com/problems/game-play-analysis-i/) | [无] | [MySQL](0511-Game-Play-Analysis-I/) | | | | | | | | | 570 | [Managers with at Least 5 Direct Reports](https://leetcode.com/problems/managers-with-at-least-5-direct-reports/) | [solution](https://leetcode.com/problems/managers-with-at-least-5-direct-reports/solution/) | [MySQL](0570-Managers-with-at-Least-5-Direct-Reports/) | | | | | | | | | 580 | [Count Student Number in Departments](https://leetcode.com/problems/count-student-number-in-departments/) | [solution](https://leetcode.com/problems/count-student-number-in-departments/solution/) | [MySQL](0580-Count-Student-Number-in-Departments/) | | | | | | | | | 584 | [Find Customer Referee](https://leetcode.com/problems/find-customer-referee/) | [solution](https://leetcode.com/problems/find-customer-referee/solution/) | [MySQL](0584-Find-Customer-Referee/) | IFNULL | | | | | | | | 586 | [Customer Placing the Largest Number of Orders](https://leetcode.com/problems/customer-placing-the-largest-number-of-orders/) | [solution](https://leetcode.com/problems/customer-placing-the-largest-number-of-orders/solution/) | [MySQL](0586-Customer-Placing-the-Largest-Number-of-Orders/) | ORDER BY and LIMIT 1 to get max/min value| | | | | | | | 595 | [Big Countries](https://leetcode.com/problems/big-countries/) | [solution](https://leetcode.com/problems/big-countries/solution/) | [MySQL](0595-Big-Countries/) | | | | | | | | | 607 | [Sales Person](https://leetcode.com/problems/sales-person/) | [solution](https://leetcode.com/problems/sales-person/solution/) | [MySQL](0607-Sales-Person/) | | | 608 | [Tree Node](https://leetcode.com/problems/tree-node/) | [solution](https://leetcode.com/problems/tree-node/solution/) | [MySQL](0608-Tree-Node/) | IF or CASE | | | | | | | | 619 | [Biggest Single Number](https://leetcode.com/problems/biggest-single-number/) | [solution](https://leetcode.com/problems/biggest-single-number/solution/) | [MySQL](0619-Biggest-Single-Number/) | | | | | | | | | 627 | [Swap Salary](https://leetcode.com/problems/swap-salary/) | [solution](https://leetcode.com/problems/swap-salary/solution/) | [MySQL](0627-Swap-Salary/) | IF or CASE | | | | | | | | 1050 | [Actors and Directors Who Cooperated At Least Three Times](https://leetcode.com/problems/actors-and-directors-who-cooperated-at-least-three-times/) | [无] | [MySQL](1050-Actors-and-Directors-Who-Cooperated-At-Least-Three-Times/) | | | | | | | | | 1084 | [Sales Analysis III](https://leetcode.com/problems/sales-analysis-iii/) | [无] | [MySQL](1084-Sales-Analysis-III/) | | | | | | | | | 1112 | [Highest Grade For Each Student](https://leetcode.com/problems/highest-grade-for-each-student/) | [无] | [MySQL](1112-Highest-Grade-For-Each-Student/) | | | | | | | | | 1141 | [User Activity for the Past 30 Days I](https://leetcode.com/problems/user-activity-for-the-past-30-days-i/) | [无] | [MySQL](1141-User-Activity-for-the-Past-30-Days-I/) | | | | | | | | | 1148 | [Article Views I](https://leetcode.com/problems/article-views-i/) | [无] | [MySQL](1148-Article-Views-I/) | | | | | | | | | 1158 | [Market Analysis I](https://leetcode.com/problems/market-analysis-i/) | [无] | [MySQL](1158-Market-Analysis-I/) | The diff between WHERE and AND in LEFT JOIN | | | | | | | | 1173 | [Immediate Food Delivery I](https://leetcode.com/problems/immediate-food-delivery-i/) | [无] | [MySQL](1173-Immediate-Food-Delivery-I/) | | | | | | | | | 1211 | [Queries Quality and Percentage](https://leetcode.com/problems/queries-quality-and-percentage/) | [无] | [MySQL](1211-Queries-Quality-and-Percentage/)| | | | | | | | | 1251 | [Average Selling Price](https://leetcode.com/problems/average-selling-price/) | [无] | [MySQL](1251-Average-Selling-Price/) | | | | | | | | | 1264 | [Page Recommendations](https://leetcode.com/problems/page-recommendations/) | [无] | [MySQL](1264-Page-Recommendations/) | | | | | | | | | 1280 | [Students and Examinations](https://leetcode.com/problems/students-and-examinations/) | [无] | [MySQL](1280-Students-and-Examinations/) | | | | | | | | | 1303 | [Find the