Learn SQL in your browser
A free SQL tutorial in short lessons on one shop database. Every example runs on real PostgreSQL in your browser, and the page checks your answers.
DbSchema Blog
Database design, migrations, SQL and everyday database work — explained with practical examples.
DbSchema Cross-Platform Database Design Tool for Windows, macOS, and Linux
DbSchema runs natively on Windows, macOS and Linux from one installation kit. Which package to take per OS, and how to move a .dbs model between them.
Best SQL Editor for Mac/Linux/Windows in 2026 | MySQL, PostgreSQL
Which SQL editor to use on macOS, Linux and Windows in 2026, compared on OS support, engines, free tier, offline use, query building and price.
Antijoins, semijoins, and some generalized quantifiers in SQL | DbSchema
Learn about a common SQL pattern used to find rows in one table that have no matching rows in another. And some related counting problems.
SQL INTERSECT Operator: Compare Common Rows Across Queries | DbSchema
Learn SQL INTERSECT with examples, INTERSECT vs INNER JOIN, support notes, and FAQs. Find common rows faster and validate results in DbSchema.
SQL CASE Expression Explained with Practical Examples
What the SQL CASE expression is, simple vs searched syntax, and examples in SELECT, ORDER BY, GROUP BY, UPDATE, INSERT, DELETE, and aggregate queries.
SQL Tutorial for Beginners with Real Examples | DbSchema
Learn SQL basics and database fundamentals with real-world examples, core concepts, and practical next steps.
SQL UNION Operator: UNION vs UNION ALL with Examples | DbSchema
Learn SQL UNION and UNION ALL with syntax, duplicate rules, ORDER BY tips, comparisons, and FAQs. Build combined result queries faster in DbSchema.
SQL Syntax Explained with Core Commands and Examples
How SQL statements are structured, a runnable example per command family, where engine syntax differs, and how to read a syntax error.
SQL SELECT Statement: Syntax, Examples, and Query Order | DbSchema
Learn the SQL SELECT statement with syntax, WHERE, DISTINCT, JOINs, GROUP BY, ORDER BY, subqueries, and FAQs. Build queries visually in DbSchema.
SQL AND, OR, NOT Operators Explained with Examples | DbSchema
SQL AND, OR and NOT explained with runnable examples: what each returns, why precedence breaks AND/OR combinations, and how NOT behaves against NULL.