Mention StaticPool for in-memory db with FastAPI

[abrahammurciano]

To use a :memory: database in a multithreaded scenario, the same connection object must be shared among threads, since the database exists only within the scope of that connection. The StaticPool implementation will maintain a single connection globally

https://docs.sqlalchemy.org/en/14/dialects/sqlite.html#using-a-memory-database-in-multiple-threads

I think it is important that we mention this here, as anyone trying to learn to use FastAPI/SQLModel will likely start by using an in-memory database. If they are unaware of this detail, they will encounter very confusing bugs which will be near impossible to debug.

[github-actions]

📝 Docs preview for commit 5c85706 at: https://637df0c0501ee11434d75902--sqlmodel.netlify.app

[github-actions]

📝 Docs preview for commit 54cee8a at: https://639cdfe91f184e00743a2cdd--sqlmodel.netlify.app

[tiangolo]

Thanks!

I would expect people following the tutorial would follow it as-is, with a database in a file, that can also be explored using SQLite Explorer.

Then I would expect them to use in-memory DBs for testing, as it's a more advanced feature. And it is documented in that section: https://sqlmodel.tiangolo.com/tutorial/fastapi/tests/#configure-the-in-memory-database

So I'll pass on this, but thanks for the interest! ☕