How do I combine two $and statements in an $or statement in mongodb?

Question

I\'m searching mongodb for all messages from a person A to person B as well as all statements from person B to person A. That way I can make a conversation

from: person

Answer 1

I'm unfamiliar with the collection function you're calling and do not know what the req object you're referring to is, so take my answer with a grain of a salt.

It seems to me that you're making this much more complicated than it really needs to be. Your $and statement is trivial enough that it does not need the $and keyword:

collection.find({
    receiver: req.user._id,
    sender:   req.body.sender
})

Now, $and and $or work exactly the same way: they take an array of objects. So let's write what I assume you intended your query to be:

collection.find({
    $or: [{
        receiver: req.user._id,
        sender:   req.body.sender
    }, {
        receiver: req.body.sender,
        sender:   req.user_id
    }]
})