How to configure sequelize to return embedded array in a one-to-many association?

Question

here is the deal:

I have two models - User and House
User has many houses
House belongs to a User

I've entered some dummy data and created a minimal express app to serve an api
I want to return a list of users and include each users houses.

the api endpoint looks like this:

router.get('/users', function(req, res,next) {
  models.User.findAll({
      include: [ models.House ],
      raw: true // returns result-set as a clean json...
  })
  .then(function(users) {
      d('num users found: ' + users.length);
      res.json(users);
  })
  .catch(function(err){
      d('DB ERROR: '+err.message);
      next(err);
  });

});

The default behavior of Sequelize is to return multiple instances of the same User data, each time with a different house data like so:

[
  {
    id: 1,
    first_name: "aa",
    last_name: "aaaaaa",
    email: "[email protected]",
    Houses.id: 1,
    Houses.description: "house 1 desc",
    Houses.user_id: 1
  },
  {
    id: 1,
    first_name: "aa",
    last_name: "aaaaaa",
    email: "[email protected]",
    Houses.id: 3,
    Houses.description: "house 3 desc",
    Houses.user_id: 1
  },
  {
    id: 2,
    first_name: "bb",
    last_name: "bbbbbb",
    email: "[email protected]",
    Houses.id: 2,
    Houses.description: "house 2",
    Houses.user_id: 2
  }
]

Can I get an array of houses embedded in the owning user?
Is there a way to configure Sequelize to return the data like so:

[
  {
    id: 1,
    first_name: "aa",
    last_name: "aaaaaa",
    email: "[email protected]",
    Houses:[
       {
          id: 1,
          description: "house 1 desc",
          user_id: 1
       },
       {
          id: 3,
          description: "house 3 desc",
          user_id: 1
       },
    ]
  },

  {
    id: 2,
    first_name: "bb",
    last_name: "bbbbbb",
    email: "[email protected]",
    Houses:[
       {
          id: 2,
          description: "house 2",
          user_id: 2
       }
    ]
  }
]

If the answer is no, can you recommend of a way to parse the data into such a structure?

The User Model:

module.exports = function(sequelize, DataTypes) {

  var User = sequelize.define('User', {

        first_name: DataTypes.STRING,
        last_name: DataTypes.STRING,
        email: DataTypes.STRING

    }, 
    {
      classMethods: {
        associate: function(models) {
          User.hasMany(models.House)
        }
      }
  });

  return User;
};

The house model:

module.exports = function(sequelize, DataTypes) {
  var House = sequelize.define("House", {
      description: DataTypes.TEXT
  }, 
  {
    classMethods: {
      associate: function(models) {
        House.belongsTo(models.User);
      }
    }
  });

  return House;
};

Answer 1

I had a similar problem and just found a solution that seems to work in my case:

router.get('/users', function(req, res, next) {
  models.User.findAll({
      include: [ {model: models.House, as: 'houses'} ],
      raw: false // returns result-set as sequelize object...
  })
  .then(function(users) {
      users = users.get(); //turns sequelize object into json
      d('num users found: ' + users.length);
      res.json(users);
  })
  .catch(function(err){
      d('DB ERROR: '+err.message);
      next(err);
  });

});

Set raw to false (or let it default to that), then, anytime you need to get the raw json before the res.json, use users.get() ("users" now being a sequelize instance) and you can get the json of that sequelize object that is now an object with an array of its associations!

Answer 2

 models.User.findAll({
      include: [ models.House ],
      nest: true
  })

add nest attribute to your query
remove raw true

for more related to issue
github-sequelize-issue 3885
stackoverflow-questions-61532849