SQL for humans.
SQL isn’t just for people with “data” in their job title—it’s a skill anyone can learn.
Whether you’ve never written a query or you use them every day, we aim to provide clear, practical examples useful at any skill level.
Not sure where to start?
SQL Prequel
Start here if you’re new to databases.
These articles explain the core concepts and terminology that make SQL easier to understand before you begin writing queries.
Topics include:
- What SQL is and how databases work
- Database objects and terminology
- Different SQL platforms and flavors
- How SQL fits into modern data systems
Writing SQL
Learn how to write SQL queries step by step.
These tutorials introduce common clauses and patterns used to retrieve, filter, sort, and summarize data.
Topics include:
- SELECT, WHERE, and ORDER BY
- GROUP BY and aggregation
- CASE expressions
- Window functions and query patterns
Database Design
Explore how data is structured behind the scenes.
These posts cover data modeling, relationships, and design principles that shape how databases store information.
Topics include:
- Database relationships and cardinality
- Normalization and data organization
- Star and snowflake schemas
- Database constraints and integrity
Better SQL
Improve the quality of your queries.
These articles share best practices that make SQL easier to read, maintain, and collaborate on with others.
Topics include:
- SQL formatting and readability
- Writing maintainable queries
- SQL style and conventions
- Professional SQL practices
SQL Troubleshooting
When queries don’t behave as expected, this is the place to look.
These guides help you diagnose problems, understand common pitfalls, and debug SQL issues.
Topics include:
- SQL error handling
- Troubleshooting query results
- Debugging techniques
- Understanding common SQL mistakes