[ExpressJS with Sequelize] equelize.js will be the place to bootstrap our ORM and define relationships. We will define our models in their respective files and app.js will be our Express app. #nodejs #expressjs #mysql

sequelize.js

const Sequelize = require('sequelize')
// models is optional based on app
const UserModel = require('./models/user')
const BlogModel = require('./models/blog')
const TagModel = require('./models/tag')

const dbname = 'DB_NAME';
const dbuser = 'DB_USER';
const dbpass = 'DB_PASS';

const sequelize = new Sequelize(dbname, dbuser, dbpass, {
  host: 'localhost',
  dialect: 'mysql',
  pool: {
    max: 10,
    min: 0,
    acquire: 30000, // in ms
    idle: 10000 // in ms
  }
})

/* -- MODEL DEFINITION -- 
* 
*/
const User = UserModel(sequelize, Sequelize)
// BlogTag will be our way of tracking relationship between Blog and Tag models
// each Blog can have multiple tags and each Tag can have multiple blogs
const BlogTag = sequelize.define('blog_tag', {})
const Blog = BlogModel(sequelize, Sequelize)
const Tag = TagModel(sequelize, Sequelize)

/* -- MODEL RELATIONSHIP -- */
Blog.belongsToMany(Tag, { through: BlogTag, unique: false })
Tag.belongsToMany(Blog, { through: BlogTag, unique: false })
Blog.belongsTo(User);

/* SYNC DATABASE ORM */
sequelize.sync({ force: true })
  .then(() => {
    console.log(`Database & tables created!`)
  })

module.exports = {
  User,
  Blog,
  Tag
}