Sequelize Associations

README.md

File Structure:

• seed_database.js
• config.json
• models/
  • index.js
  • User.js
  • UserType.js

Make sure that the SQL configs are in config.json.

$ node seed_database.js

It's important to node that the models/User.js contains an associate function. Read more at: http://sequelizejs.com/articles/express#models-index-js

index.js

"use strict";

var fs        = require("fs");
var path      = require("path");
var Sequelize = require("sequelize");
var basename  = path.basename(module.filename);
var env       = process.env.NODE_ENV || "development";
var config    = require('../config.json')[env];
var sequelize = new Sequelize(config.database, config.username, config.password, config);
var db        = {};

fs
  .readdirSync(__dirname)
  .filter(function(file) {
    return (file.indexOf(".") !== 0) && (file !== basename);
  })
  .forEach(function(file) {
    var model = sequelize["import"](path.join(__dirname, file));
    db[model.name] = model;
  });

Object.keys(db).forEach(function(modelName) {
  if ("associate" in db[modelName]) {
    db[modelName].associate(db);
  }
});

db.sequelize = sequelize;
db.Sequelize = Sequelize;

module.exports = db;

seed_database.js

var Sequelize = require('sequelize');

var env       = process.NODE_ENV || 'development';
var config    = require('./config.json')[env];

// Connect to the database
var sequelize = new Sequelize(config.database, config.username, config.password, config);

// Import models
var models    = require('./models');

// http://runnable.com/UXgrne_v2oZyAACN/how-to-use-associations-in-sequelize-for-node-js
var chainer = new Sequelize.Utils.QueryChainer;
var admin, adminUserType;

models.sequelize.sync({force: true})
  .then(function() {
    /**
     * We want to call `build` instead of `create`
     * since `create` invokes `build` and `save`.
     * We want to `save` AFTER dependencies are created.
     */

    // Build the instances (do not invoke save yet!)
    admin = models.User.build({
      username: 'Admin',
      password: 'p@$$w0rd'
    });

    // Build the instances (do not invoke save yet!)
    adminUserType = models.UserType.build({
      role: 'administrator'
    });

    // Explicitly state how the rows should be saved.
    chainer
      .add(adminUserType.save())
      .add(admin.save());

    // Execute everything in the chainer
    chainer.run()
    //On success, set the user
    .on('success', function() {
      // Set the userType
      admin.setUserType(adminUserType);
    });
  })

User.js

'use strict';
/**
 * Customer Address table for 1 to many relationship for a
 * customer having multiple addresses
 * @param  {Object} sequelize Sequelize instance
 * @param  {Object} DataTypes DataTypes enum
 * @return {Object}           User definition object
 */
module.exports = function(sequelize, DataTypes) {
  var User = sequelize.define('User', {
    id: {
      type: DataTypes.INTEGER,
      allowNull: false,
      autoIncrement: true,
      primaryKey: true,
      isInt: true
    },
    username: {
      type: DataTypes.STRING,
      allowNull: false
    },
    password: {
      type: DataTypes.STRING,
      allowNull: false
    }
  }, {
    classMethods: {
      // Creates an association function that is run AFTER all the models are loaded into sequelize.
      associate: function (models) {
        User.belongsTo(models.UserType);
      }
    }
  });

  return User;
}

UserType.js

'use strict';

/**
 * Customer Address table for 1 to many relationship for a
 * customer having multiple addresses
 * @param  {Object} sequelize Sequelize instance
 * @param  {Object} DataTypes DataTypes enum
 * @return {Object}           User definition object
 */
module.exports = function(sequelize, DataTypes) {
  var UserType = sequelize.define('UserType', {
    id: {
      type: DataTypes.INTEGER,
      allowNull: false,
      autoIncrement: true,
      primaryKey: true,
      isInt: true
    },
    role: {
      type: DataTypes.STRING,
      allowNull: false
    }
  });

  return UserType;
}