But I need to filter the data of a collection by reference to its _id in another collection.
I need to display only the projects of a given user.
Out of the question restructure the base.
users: {_id: ObjectId ("..."), name: "user", ...}
Projects: { _id: ObjectId ("...") , name: "project1", ...}
In short, I want to pass the user id and it bring me all his projects without changing the structure above. Is it possible?
MongoDB does not support joins .
Unfortunately, its structure does not fit MongoDB's operation.
Mongodb is a non-relational database, you should centralize the data of each query in the same document.
The data from the collection usuariosProjetos should be part of the collection usuarios .
Adding that from its version 3.4, mongodb brings the $ lookup operator, which allows joining records of two collections, from some common value between the two. But that's just it. Complex joins as in relational banking, forget.
