I want to use the collections as DBs! That is, make a connection from node.js where you can use a collection as a normal database?
The purpose of this is that I'm going to create two totally different apps, with different collections and documents, but there are data that I need to relate between the two apps. And if the two apps are using the same database, it would be much easier for me.
Well.. MongoDB doesnt do that, what can you do is something like give a prefix name to your collections, "projectA_Users , projectB_Users" and to relate data use the $lookup Aggregate operator to get your relationship. I see something like that on FireBase that you can create a collection inside a document and use find, update, remove on it (here)