How to fetch value from one schema and update in other using middlewares in mongoose

Question

While updating Movie documents, get value from User collection and save it with the documents getting updated in Movie.

Movie.pre('update', function (next) {
   var id = this._update.$set.userid;
   var some = this;
   User.findOne({userid: id}, function(err, post) {
       // how should we add the firstname to current movie document and
       let update query update it all. Something like this...
       some.firstname = post.firstname;
       next();
   });
});

// update query
Movie.statics.saveMovieDetails = function(requestData, callback) {
this.update({userid:requestData.userid},
    { $set:{
            userid   : requestData.userid,
            name     : requestData.name,
            location : requestData.location,
            language : requestData.language,
            date     : requestData.date
        }
    },{upsert:true}, callback);
};

Answer 1

This is how i did it. Correct me if i am wrong or if there is any better way to solve this problem.

Movie.pre('update', function (next) {
  var id = this._update.$set.userid;
  var some = this;
  User.findOne({userid: id}, function(err, post) {
      some._update.$set.firstname = post.firstname;
      next();
  });
});