How to support both PostgreSQL and SQL Server in a Node.JS application?

I'm currently developing a Node.js app that needs to be able to switch between PostgreSQL and SQL Server databases. Both databases have identical tables and the operations will also be identical (basic CRUD, nothing fancy).

I've done research, and know that there are enough libraries around to access both databases.

Ideally I'd like to use a ORM and just let that handle the differences. However, I can't seem to find an ORM framework that does both. In fact, I can't locate any ORM that supports SQL Server, while almost all support Postgres.

So my question: is there an ORM that supports both? And if there isn't, are there other abstraction tools/frameworks around that will make my developer life easier?

There is a certain amount of YAGNI here, but if you are unable to find an ORM that supports both, your next best bet is to just use an Adapter Pattern and ensure you're not using the ORM directly in your code, but through a wrapper. Then if / when you need support for SQL Server, you can create the implementation for the wrapper which will replace the PostgreSQL implementation.