我认为你应该使用 belongsToMany 关联在这里.

I think you should use belongsToMany association here.

你可以这样定义关联

Product.belongsToMany(Category, { through: ProductCategory, foreignKey: 'product_id' });
Category.belongsToMany(Product, { through: ProductCategory, foreignKey: 'category_id' });

查询可以是

Product.findAll({
  include: [Category]
}).then((res) => {
  console.log(res);
})