We use in-memory sqlite databases for unit testing a MySQL backed web service. It’s great! You can build and test the code without setting up a MySQL server and

We use in-memory sqlite databases for unit testing a MySQL backed web service. It’s great! You can build and test the code without setting up a MySQL server and no risk of state leaking like you said. The syntax isn’t exactly the same but we have a small wrapper layer that rewrites MySQL-specific queries into their SQLite equivalents. The only real downside is that it’s a C dependency which makes cross compiling a bit of a pain until you figure out the magic incantation the compiler wants.