Postgresql use through DataSources

Hello,

I completed the Odyssey courses (great job). The one thing that is not clear to me in my current use case is how to integrate Postgresql without the knex (I do not want to learn/use the knex ORM).

Do you have a reference implementation to use Apollo-Server with Postgresql that does not require knex? Is there any graphql/Apollo specific reason that ORMs are suggested to be used with Apollo-server?

I am hitting a saturation point of learning new technologies (do I need to use Hasura, TypeGraphl, Prisma, or other ORMs to get an app to production?) to get my test application up and running with postgesql and apollo-server.

Thanks,

Ivan