SQL Problem Solutions

This repository contains my solutions to SQL problems. This collection features SQL problems solved using SQL Server, categorized by difficulty: Easy, Medium, and Hard. Each entry includes a link to the problem and my solution.

If you have feedback or suggestions, feel free to open an issue or reach out!

LeetCode

Easy

• 2356. Number of Unique Subjects Taught by Each Teacher - Solution

• 1978. Employees Whose Manager Left the Company - Solution

• 1789. Primary Department for Each Employee - Solution

• 1757. Recyclable and Low Fat Products - Solution

• 1731. The Number of Employees Which Report to Each Employee - Solution

• 1729. Find Followers Count - Solution

• 1683. Invalid Tweets - Solution

• 1667. Fix Names in a Table - Solution

• 1661. Average Time of Process per Machine - Solution

• 1633. Percentage of Users Attended a Contest - Solution

• 1581. Customer Who Visited but Did Not Make Any Transactions - Solution

• 1527. Patients With a Condition - Solution

• 1517. Find Users With Valid E-Mails - Solution

• 1484. Group Sold Products By The Date - Solution

• 1378. Replace Employee ID With The Unique Iden - Solution

• 1327. List the Products Ordered in a Period - Solution

• 1280. Students and Examinations - Solution

• 1251. Average Selling Price - Solution

• 1211. Queries Quality and Percentage - Solution

• 1148. Article Views I - Solution

• 1141. User Activity for the Past 30 Days I - Solution

• 511. Game Play Analysis I - Solution

• 1075. Project Employees I - Solution

• 1068. Product Sales Analysis I - Solution

• 1050. Actors and Directors Who Cooperated At Lea - Solution

• 627. Swap Salary - Solution

• 620. Not Boring Movies - Solution

• 619. Biggest Single Number - Solution

• 610. Triangle Judgement - Solution

• 607. Sales Person - Solution

• 596. Classes More Than 5 Students - Solution

• 595. Big Countries - Solution

• 586. Customer Placing the Largest Number of Orders - Solution

• 584. Find Customer Referee - Solution

• 577. Employee Bonus - Solution

• 197. Rising Temperature - Solution

• 196. Delete Duplicate Emails - Solution

• 183. Customers Who Never Order - Solution

• 182. Duplicate Emails - Solution

• 181. Employees Earning More Than Their Manager - Solution

• 175. Combine Two Tables - Solution

• 1965. Employees With Missing Information - Solution

• 1890. The Latest Login in 2020 - Solution

• 1873. Calculate Special Bonus - Solution

• 1795. Rearrange Products Table - Solution

• 1741. Find Total Time Spent by Each Employee - Solution

• 1693. Daily Leads and Partners - Solution

• 1587. Bank Account Summary II - Solution

• 1407. Top Travellers - Solution

• 1179. Reformat Department Table - Solution

• 1084. Sales Analysis III - Solution

Medium

• 1934. Confirmation Rate - Solution

• 1907. Count Salary Categories - Solution

• 1341. Movie Rating - Solution

• 1321. Restaurant Growth - Solution

• 1204. Last Person to Fit in the Bus - Solution

• 1193. Monthly Transactions I - Solution

• 1174. Immediate Food Delivery II - Solution

• 1164. Product Price at a Given Date - Solution

• 550. Game Play Analysis IV - Solution

• 1070. Product Sales Analysis III - Solution

• 1045. Customers Who Bought All Products - Solution

• 626. Exchange Seats - Solution

• 602. Friend Requests II: Who Has the Most Friends - Solution

• 585. Investments in 2016 - Solution

• 570. Managers with at Least 5 Direct Reports - Solution

• 180. Consecutive Numbers - Solution

• 176. Second Highest Salary - Solution

• 3220. Odd and Even Transactions - Solution

• 1393. Capital Gain/Loss - Solution

• 1158. Market Analysis I - Solution

• 608. Tree Node - Solution

• 184. Department Highest Salary - Solution

• 178. Rank Scores - Solution

• 177. Nth Highest Salary - Solution

Hard

• 185. Department Top Three Salaries - Solution

• 601. Human Traffic of Stadium - Solution

• 262. Trips and Users - Solution