CODEWITHSUNDEEP
node.jssails.jswaterline
Andi S.
Andi S.

Reputation: 163

Efficient queries across several models using Sails.js waterline

I am trying to find an efficient way to retrieve results which spread across several models. In my example I have three models:

A simplified version of my models looks like this:

// Video.js

module.exports = {

attributes: {
    title: {
      type: 'string'
    },
    creator: {
      model: 'User'
    }
  }
};


// User.js

module.exports = {

  attributes: {
    user_name: {
      type: 'string'
    }
  }
};


 // Follower.js

module.exports = {

  attributes: {
    user: {
      model: 'User'
    },
    follower: {
      model: 'User'
    }
  }
};

I realize that I could store the many to many association as a Collection in User directly, but I also store other values along with it such as when a user started to follow another user and from which destination he did so. In addition, I store lots of similar data and I would like to keep the core Models like Video and User lean.

So now I am trying to get the 10 latest videos (the creation datetime is stored in the createdAt attribute automatically added by waterline) which were created by a user which a given user follows.

Starting with this given user (let's call him queryingUser) I am trying to get all the users he follows and use them as input to search for videos. I imagine a call to look like this:

Follower.find({where: {follower: queryingUser} , select: ['user']}).exec(function (err, users){

    var userArray = [];

    for (var i=0; i< users.length; i++) userArray.push(users[i].user);

    Video.find({ where: {creator: userArray}, limit: 10, sort: 'createdAt DESC' }).exec(function (err, videos){
        // videos should contain the desired result
    });
});

I think according to the waterline docs a call like this should work, however, it doesn't seem to retrieve any results.

Am I doing something wrong? Is there a different approach which would lead to the desired result in an efficient way?

Upvotes: 1

Views: 87

Answers (1)

Andi S.
Andi S.

Reputation: 163

Never mind, it does actually work. I made a mistake elsewhere in my code, but after I fixed it I got the example to work. Maybe it is still helpful for someone else.

Upvotes: 1

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