猫鼬从模型中删除

Question

My MongoDB has a sessions collection that is created by a module. The collection has no model or anything since it is not created by Mongoose.

How can I access this collection without specifying it's model?

I tried the following:

mongoose.connection.db.sessions.remove({'session.userId': userId}, function(e, found) {
    console.log(found);
    res.json({success: true});
});

Although I received the error of: Cannot read property 'remove' of undefined

Answer 1

Querying the collection directly will only solve part of your problem.

From the looks of it, you're using express-session and connect-mongo to manage sessions. This will store the session data ( req.session ) as a JSON string in the database:

{
  "_id": "fLBj_McMFM-7PwVNsv9ov88vOAgoNiDa",
  "session": "{\"cookie\":{\"originalMaxAge\":null,\"expires\":null,\"httpOnly\":true,\"path\":\"/\"},\"userId\":\"my-user-id\"}",
  "expires": ISODate("2016-07-09T08:47:38.156Z")
}

As you can see, session is a string, not an object, so you can't query it directly using session.userId .

If you can't use req.session.destroy() , you need to perform a regular expression query to match against the user id in the JSON string:

let collection = mongoose.connection.db.collection('sessions');
let query      = new RegExp(`"userId":"${userId}"`);
collection.remove({ session : query }, function(e, found) {
  console.log(found);
  res.json({success: true});
});

It's probably best if userId is first run through something like escape-string-regexp to make sure that any special characters are escaped properly.

Note that this isn't a fast query, especially if you have a lot of sessions in your database.

EDIT : I just found the stringify option for connect-mongo which, if set to false , should write the session data as a regular object to MongoDB, and not as a JSON string.