text: // import models
  const Product = require('./Product');
  const Category = require('./Category');
  const Tag = require('./Tag');
  const ProductTag = require('./ProductTag');
  
  // Products belongsTo Category
  Product.belongsTo(Category,{
    foreignKey: 'category_id',
    onDelete: 'CASCADE'
  });
  
  // Categories have many Products
  Category.hasMany(Product, {
    foreignKey: 'category_id',
  });
  // Products belongToMany Tags (through ProductTag)
  Product.belongsToMany(Tag, {
    through: ProductTag,
    foreignKey: 'product_id',
    onDelete: 'CASCADE'
  });
  // Tags belongToMany Products (through ProductTag)
  Tag.belongsToMany(Product, {
      through: ProductTag,
      foreignKey: 'tag_id',
      onDelete: 'CASCADE'
    },
  );
  
  module.exports = {
    Product,
    Category,
    Tag,
    ProductTag,
  };
  