Official question repository for SQL Playground Online
This public repository contains SQL practice questions used in the SQL Playground Online website.
Users can browse the questions, suggest new ones via pull requests, report issues, and help improve existing questions.
- Make the question bank public and transparent
- Allow community contributions such as new questions and improvements
- Serve as a support and backup repository for the main application
- Easy — Basic SELECT, filtering, aggregation, and dates
- Medium — Joins, subqueries, and grouping
- Hard — Window functions, self-joins, and advanced queries
- Fork this repository
- Create a new branch
- Add or modify questions
- Submit a pull request
You can contribute by:
- Adding new SQL questions
- Improving descriptions or sample data
- Fixing bugs or unclear questions
- Suggesting better solutions
Each question is stored as a JavaScript object with the following fields:
id— Unique identifiertitle— Question titledifficulty— Easy / Medium / Harddescription— Problem statementconstraints— Output requirements and rulestags— Array of tagssolutionQuery— Correct SQL solutiontables— Table schemas and sample data
- Write clear and unambiguous problem statements
- Provide realistic sample data, preferably 8+ rows
- Include proper constraints such as ordering and column names
- Make sure the solution query is correct
- Cover different SQL concepts
MIT License — Feel free to use these questions in your own projects with attribution.
Happy SQL Learning! ✨
Main Application: SQL Playground Online
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