Leetcode-SQL-50 Solutions

Welcome to the repository for the solutions to the top 50 SQL questions on LeetCode! This repository contains my solutions to the SQL problems listed in the LeetCode Top SQL 50 Study Plan.

My Leetcode

Table of Contents

• Introduction
• Solutions
  • Select
  • Basic Joins
  • Basic Aggregate Functions
  • Sorting and Grouping
  • Advanced Select and Joins
  • Subqueries
  • Advanced String Functions / Regex / Clause
• Usage
• Contact

Introduction

This repository provides solutions to the top 50 SQL problems on LeetCode. Each problem is solved and the solution is provided in a SQL file. These problems cover various SQL concepts and are aimed at improving SQL querying skills.

Solutions

The solutions are organized in the following structure:

Select

• Recyclable and Low Fat Products
• Find Customer Referee
• Big Countries
• Article Views I
• Invalid Tweets

Basic Joins

• Replace Employee ID With The Unique Identifier
• Product Sales Analysis I
• Customer Who Visited but Did Not Make Any Transactions
• Rising Temperature
• Average Time of Process per Machine
• Employee Bonus
• Students and Examinations
• Managers with at Least 5 Direct Reports
• Confirmation Rate

Basic Aggregate Functions

• Not Boring Movies
• Average Selling Price
• Project Employees I
• Percentage of Users Attended a Contest
• Queries Quality and Percentage
• Monthly Transactions I
• Immediate Food Delivery II
• Game Play Analysis IV

Sorting and Grouping

• Number of Unique Subjects Taught by Each Teacher
• User Activity for the Past 30 Days I
• Product Sales Analysis III
• Classes More Than 5 Students
• Find Followers Count
• Biggest Single Number
• Customers Who Bought All Products

Advanced Select and Joins

• The Number of Employees Which Report to Each Employee
• Primary Department for Each Employee
• Triangle Judgement
• Consecutive Numbers
• Product Price at a Given Date
• Last Person to Fit in the Bus
• Count Salary Categories

Subqueries

• Employees Whose Manager Left the Company
• Exchange Seats
• Movie Rating
• Restaurant Growth
• Friend Requests II: Who Has the Most Friends
• Investments in 2016
• Department Top Three Salaries

Advanced String Functions / Regex / Clause

• Fix Names in a Table
• Patients With a Condition
• Delete Duplicate Emails
• Second Highest Salary
• Group Sold Products By The Date
• List the Products Ordered in a Period
• Find Users With Valid E-Mails

Usage

1. Clone this repository to your local machine:

git clone https://github.com/Rakshitgupta9/Leetcode-SQL-50.git

2. Navigate to the directory:

cd Leetcode-SQL-50

3. Open the SQL file for the problem you want to review.

You can run these SQL queries on your local SQL server or any SQL-based platform.

Contact

If you have any questions or suggestions, feel free to reach out to me at:

• Name: Rakshit Gupta
• Email: guptarakshit9858@gmail.com
• LinkedIn: Rakshit Gupta

Thank you for visiting this repository. Happy coding!