app2-api/modules/blog/category.model.js

module.exports = function (sequelize, DataTypes) {
	const Category = sequelize.define('Category', {
		id: {
			type: DataTypes.INTEGER,
			autoIncrement: true,
			primaryKey: true
		},
		name: {
			type: DataTypes.STRING,
		    allowNull: false
		},
		sort: { 
			type: DataTypes.INTEGER,
			defaultValue: 0,
			allowNull: false,
		}
	}, {
		tableName: 'category',
		freezeTableName: true,
		timestamps: false
	});

	/*Category.beforeCreate((category) => {
		//category.dataValues.id = Math.floor(Math.random() * (999 - 8)) + 8;
	})*/

	Category.associate = function (models) {
		Category.Posts = Category.belongsToMany(models.Post, { 
			through: models.PostCategory,
			foreignKey: 'categoryId'
		});
	};

	return Category;
};