const { DataTypes, Model } = require('sequelize') module.exports = (sequelize) => { class BookSeries extends Model { static removeByIds(seriesId = null, bookId = null) { const where = {} if (seriesId) where.seriesId = seriesId if (bookId) where.bookId = bookId return this.destroy({ where }) } } BookSeries.init({ id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true }, sequence: DataTypes.STRING }, { sequelize, modelName: 'bookSeries', timestamps: true, updatedAt: false }) // Super Many-to-Many // ref: https://sequelize.org/docs/v6/advanced-association-concepts/advanced-many-to-many/#the-best-of-both-worlds-the-super-many-to-many-relationship const { book, series } = sequelize.models book.belongsToMany(series, { through: BookSeries }) series.belongsToMany(book, { through: BookSeries }) book.hasMany(BookSeries) BookSeries.belongsTo(book) series.hasMany(BookSeries) BookSeries.belongsTo(series) return BookSeries }