This is a dependency free sql database written in python. I've intentionally tried to keep the feature set & accompanying code "simple", ignoring edge cases and optimizations so that anyone can read through and improve their understanding of how databases work.
I work with sql databases everyday but don't have deep understanding of how they work, this is an attempt to improve my understanding of their implementation. Implementing one covers a wide variety of topics like lexing, parsing, VMs, tree algorithms, serialization formats.
Check the vm tests for an idea of current features. Anything beyond that is likely to break.