Hi HN, I created rgSQL, a test suite for query engines. The project helps you TDD your own database so you can learn how to parse and execute SQL.

The tests are organised into related topics and build up concepts over time through examples in a similar way to The Little Schema book and From Nand to Tetris.

You can read more about the project at https://technicaldeft.com/posts/rgsql-a-test-suite-for-datab...

I have also written an accompanying book to guide people through the project and learn how real world databases and query engines work: https://technicaldeft.com/build-a-database-server