How to return table in JavaScript in Sails.js from multiple models

Question

I got 2 models, User and Friend. In friend i got 2 columns( UserId1, UserId2) I want to find in Friend rows where UserId1 is specified, and then from the table with these rows i want to return table with Users with Id = UserId2

index: function(req, res, next) {

  Friend.find({UserId1 : req.session.User.id}, function foundUsers(err, friends) {
    if (err) return next(err);
    // pass the array down to the /views/index.ejs page
    res.view({
      friends: friends
    });
  });
}

This code above return table with Friends(UserId1, UserId2) where UserId1 is specified, but how to return table with Users (from model User) where Id = UserId2 ??

Answer 1

So, it sounds like you're using the Friend model as a join table that represents a friendship between two users. The query you currently have in your code gets all of the records from the join table where UserId1 is the id of your logged in user, and for each of those records, you want to get a full User object for the user whose id matches the UserId2 column. If this is the case, the full code could be something like:

index: function(req, res) {

    Friend.find({UserId1 : req.session.User.id})
    .exec(function foundUsers(err, friend_records) {

        if (err) return res.serverError(err);

        // Get an array of all the UserId2 values, using sails.util.pluck,
        // which is essentially Lodash's _.pluck
        var friend_ids = sails.util.pluck(friend_records, 'id');

        // Get the User records for those users.  Using an array
        // in the criteria makes Waterline do an "in" query
        User.find({id: friend_ids}).exec(function(err, friends) {

            // pass the array down to the /views/index.ejs page
            res.view({
                friends: friends
            });

        });

    });

}

A couple of notes:

• You should almost never use next in your controller code, especially for error handling. If there's an error, handle it using a response. Save next for policies unless you really, really intend for another controller to handle the response for you.
• Sails v0.10 (currently in beta) includes support for associations, which would handle the join tables for you.