SQL

SQL Practice Solutions

This repository contains my solutions to SQL problems from platforms like HackerRank and LeetCode. The goal of this repository is to document my progress in learning SQL and showcase solutions for a variety of database query challenges.

Repository Structure

The repository is organized based on the platform and difficulty level of the problems. Here's the directory structure:

SQL/
├── README.md
├── HackerRank/
│   ├── Easy/
│   │   ├── Problem1.sql
│   │   ├── Problem2.sql
│   │   └── ...
│   ├── Medium/
│   │   ├── Problem1.sql
│   │   ├── Problem2.sql
│   │   └── ...
│   └── Hard/
│       ├── Problem1.sql
│       └── ...
├── LeetCode/
│   ├── Easy/
│   │   ├── Problem1.sql
│   │   ├── Problem2.sql
│   │   └── ...
│   ├── Medium/
│   │   ├── Problem1.sql
│   │   ├── Problem2.sql
│   │   └── ...
│   └── Hard/
│       ├── Problem1.sql
│       └── ...

Platforms

HackerRank

• Problems solved on HackerRank are divided into three categories:
  • Easy
  • Medium
  • Hard

LeetCode

• Problems solved on LeetCode follow the same categorization:
  • Easy
  • Medium
  • Hard

Problem Format

Each SQL file includes the following:

• Problem name and link
• The SQL query solution

Example format:

-- Problem: Select All Records
-- Platform: HackerRank
-- URL: https://www.hackerrank.com/challenges/select-all-records/problem

SELECT * FROM employees;

How to Use This Repository

1. Clone the repository:

   git clone https://github.com/your-username/sql-solutions.git

2. Navigate to the platform and difficulty level to view solutions.

Disclaimer

These solutions are my personal implementations. Use them to learn and understand SQL concepts. Avoid copying them directly into your own submissions for coding platforms.

Future Goals

• Practice advanced SQL concepts such as window functions, CTEs, and optimization.
• Solve more problems on additional platforms like StrataScratch and DataLemur.
• Explore practical SQL projects to apply these skills in real-world scenarios.

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Happy Querying! 🚀