Sequelize Insert Many to Many

Question

What is the right way to insert in a many-to-many relation while setting references all in one shot? I don't want to xreate objects first and then set the references in another step.

Product.belongsToMany(models.Aisle, { through: 'AisleProduct' }); 
Aisle.belongsToMany(models.Product, { through: 'AisleProduct'});

var product = models.Product
            .build({
                AisleId:[1,2]  // This does NOT work!
            });
product.save();

This does not work either

var product = models.Product.build({});
product.setAisles(AisleId:[1,2]);
product.save();

as setAisles tries to save the object which does not have an id yet and throws an exception

Answer 1

You need to create Aisles first. Sequelize doesn't support creating the associated object during the build phase of the relative.

Your code should look something like this :

models.Aisle.create({}).then(function(aisle1) {
  models.Aisle.create({}).then(function(aisle2) {

    models.Product.create({}).then(function(product) {
      product.setAisles([aisle1, aisle2]);
    });

  });
});

You can create your own beforeCreate hook that can create the Aisles via the options before you save the Product.

BelongsToMany relation adds another table to your database productAisles, which needs to be populated to save the relation, so practically you will not save any queries if you first build the Aisles and then add them to your Product.