Rewrite databases page

The idea is to rewrite the databases page on our documentation: https://www.starlette.io/database/ .

Instead of recommending databases, we should recommend pure SQLAlchemy.

cc @zzzeek (just pinging to let you know about our intentions, no need to react)

[tomchristie]

Is the reason behind databases that there was no async capabilities for it at the time?

Yes.

[gnat]

I imagine if SQLAlchemy had asyncio previously, databases would likely have never been created, even with the poor developer docs story.

https://docs.sqlalchemy.org/en/20/changelog/migration_14.html#change-3414

tl;dr: SQLAlchemy makes use of greenlet to support asyncio.

I’m not terribly familiar with the greenlet library, so if anyone can chime in with real world experiences, that would be fantastic.