node.js - Is it possible to filter a query by the attributes in the association table with sequelize?

Question

I am trying to filter my query by the attributes of the joining table

I have 2 tables Cities and Categories which I am associating through a third table CityCategory. The idea is to get the Categories associated with a City when CityCategory.year is a specific integer.

This is how I specified the associations:

module.exports = function(sequelize, DataTypes) {
    var CityCategory = sequelize.define('CityCategory', {
        year: {
            type: DataTypes.INTEGER,
            allowNull: false,
            validate: {
                notNull: true
            }
        }
    }, {
        indexes: [{
            unique: true,
            fields: ['CityId', 'CategoryId', 'year']
        }]
    });

    return CityCategory;
};

City.belongsToMany(models.Category, {
                    through: {
                        model: models.CityCategory
                    }
                });

Category.belongsToMany(models.City, {
                    through: {
                        model: models.CityCategory
                    }
                });

This is the query I'm currently, unsuccessfully using:

City.find({
        where: {id: req.params.id},
        attributes: ['id', 'name'],
        include: [{
            model: Category,
            where: {year: 2015},
            attributes: ['id', 'name', 'year']
        }]
    })
    .then(function(city) {
        ...
    });

Unfortunately I'm not sure how to tell sequelize to use the CityCategory's year attribute instead of it searching for an attribute called 'year' in the Category model...

Unhandled rejection SequelizeDatabaseError: ER_BAD_FIELD_ERROR: Unknown column 'Category.CityCategory.year' in 'where clause'

Is this possible or would I have to go and manually write my custom query?

Many thanks in advance!

edit

I've been playing around a little more and found a solution! It seems a little messy so I'm sure there must be a better way.

City.find({
    where: {id: req.params.id},
    attributes: ['id', 'name'],
    include: [{
      model: Category,
      where: [
        '`Categories.CityCategory`.`year` = 2015'
      ],
      attributes: ['id', 'name', 'year']
    }]
  })
  .then(function(city) {
    ...
  });

Answer 1

When querying the through table, you should use through.where

include: [{
  model: Category,
  through: { where: {year: 2015}},
  attributes: ['id']
}]

You might want to add required: true to turn the include to an inner join