SQL 50

This repository contains MySQL solutions for LeetCode's SQL 50 Study Plan, a curated list of problems to improve SQL query writing and database understanding.

Problem List

✨ This table will grow as new solutions are added.

Select

#	Difficulty	Problem	Solution
1757	Easy	Recyclable and Low Fat Products	Code
584	Easy	Find Customer Referee	Code
595	Easy	Big Countries	Code
1148	Easy	Article Views I	Code
1683	Easy	Invalid Tweets	Code

Basic Joins

#	Difficulty	Problem	Solution
1378	Easy	Replace Employee ID With The Unique Identifier	Code
1068	Easy	Product Sales Analysis I	Code
1581	Easy	Customer Who Visited but Did Not Make Any Transactions	Code
197	Easy	Rising Temperature	Code
1661	Easy	Average Time of Process per Machine	Code
577	Easy	Employee Bonus	Code
1280	Easy	Students and Examinations	Code
570	Medium	Managers with at Least 5 Direct Reports	Code
1934	Medium	Confirmation Rate	Code

Basic Aggregate Functions

#	Difficulty	Problem	Solution
620	Easy	Not Boring Movies	Code
1251	Easy	Average Selling Price	Code
1075	Easy	Project Employees I	Code
1633	Easy	Percentage of Users Attended a Contest	Code
1211	Easy	Queries Quality and Percentage	Code
1193	Medium	Monthly Transactions I	Code
1174	Medium	Immediate Food Delivery II	Code
550	Medium	Game Play Analysis IV	Code

Sorting and Grouping

#	Difficulty	Problem	Solution
2356	Easy	Number of Unique Subjects Taught by Each Teacher	Code
1141	Easy	User Activity for the Past 30 Days I	Code
1070	Medium	Product Sales Analysis III	Code
596	Easy	Classes With at Least 5 Students	Code
1729	Easy	Find Followers Count	Code
619	Easy	Biggest Single Number	Code
1045	Medium	Customers Who Bought All Products	Code

Advanced Select and Joins

#	Difficulty	Problem	Solution
1731	Easy	The Number of Employees Which Report to Each Employee	Code
1789	Easy	Primary Department for Each Employee	Code
610	Easy	Triangle Judgement	Code
180	Medium	Consecutive Numbers	Code
1164	Medium	Product Price at a Given Date	Code
1204	Medium	Last Person to Fit in the Bus	Code
1907	Medium	Count Salary Categories	Code

Subqueries

#	Difficulty	Problem	Solution
1978	Easy	Employees Whose Manager Left the Company	Code
626	Medium	Exchange Seats	Code
1341	Medium	Movie Rating	Code
1321	Medium	Restaurant Growth	Code
602	Medium	Friend Requests II: Who Has the Most Friends	Code
585	Medium	Investments in 2016	Code
185	Hard	Department Top Three Salaries	Code

License

Licensed under the MIT License.