SQLtest.online
A free online SQL trainer and playground with hundreds of practice tasks checked automatically on real MySQL, MariaDB, PostgreSQL, and other engines, plus lessons, a skills test, and an interview simulator.
SQLtest.online is a free platform for learning and practicing SQL in the browser. Its question bank of practice tasks runs from basic SELECT queries to analytical problems with window functions and CTEs, and every task is checked automatically: the query runs on a real database and the result is compared with the expected one. Tasks use real engines and sample databases, including Sakila on MySQL and a University database on MariaDB, alongside PostgreSQL, SQL Server, SQLite, DuckDB, and others.
Besides the tasks, it offers SQL lessons with runnable examples, an online SQL playground for MySQL, MariaDB, PostgreSQL, SQL Server, Oracle, SQLite, and Firebird, a free skills test that ends in a rank (not an official certificate), and an interview simulator. No account is needed to start; signing in only saves progress. The site has no ads and runs on donations.
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