Track 1
Foundations
Your first SQL queries
- SELECT, FROM, WHERE basics
- Filtering with comparison and logical operators
- NULL handling and IS NULL
- INNER JOIN and LEFT JOIN
- ORDER BY, LIMIT, and DISTINCT
Track 2
Practitioner
Write real database queries
- Aggregate functions and GROUP BY
- HAVING vs WHERE
- Multiple joins and self-joins
- Subqueries and EXISTS
- CASE expressions and COALESCE
Track 3
Advanced
SQL for data engineering
- Window functions: RANK, LAG, SUM OVER
- CTEs and recursive queries
- Transactions and ACID
- Indexes and EXPLAIN ANALYZE
- Schema design and normalization
Practice environment
Run every query from these lessons for free in your browser — no installation needed.
db-fiddle.com →