Bulk Insertion in Sequelize hasMany() Association - node.js

Question

First of all let me explain what I want to do. I have two model User and Product well define. I use method created by sequelize when defining association with hasMany() and belongsTo() to create my product.
user.hasMany(Product)
Product.belongsTo(User)
and I used this method to create the product from user.
User.findOne({where:{id:SomeID}}).then((userObj)=>{
userObj.createProduct(productobj).then((userObj)=>{
//product creation handling
}).catch((errorProduct)=>{
//product creation error handling
});
}).catch((error)=>{
//user creation error handling
});
My productobj is an array of json object that belongs to User.
It works fine when it's only one product but it failed when there is more than one product. So I wonder if there is any method that I can use to bulk create those products from the same user.
I may be doing it the wrong way. So if there is a better way then I will highly appreciate it. Thank you for your help.

Answer 1

The association user.hasMany(Product) will add below methods to User model.
/**
* The addAssociations mixin applied to models with hasMany.
* An example of usage is as follows:
*
* ```js
*
* User.hasMany(Role);
*
* interface UserInstance extends Sequelize.Instance<UserInstance, UserAttributes>, UserAttributes {
* // getRoles...
* // setRoles...
* addRoles: Sequelize.HasManyAddAssociationsMixin<RoleInstance, RoleId>;
* // addRole...
* // createRole...
* // removeRole...
* // removeRoles...
* // hasRole...
* // hasRoles...
* // countRoles...
* }
* ```
*
* #see https://sequelize.org/master/class/lib/associations/has-many.js~HasMany.html
* #see Instance
*/
For your case, you should use userModel.addProducts(productModels). E.g.
import { sequelize } from '../../db';
import { Model, DataTypes, HasManyAddAssociationsMixin } from 'sequelize';
class User extends Model {
public addProducts!: HasManyAddAssociationsMixin<Product, number>;
}
User.init(
{
email: {
type: DataTypes.STRING,
unique: true,
},
},
{ sequelize, modelName: 'users' },
);
class Product extends Model {}
Product.init(
{
name: DataTypes.STRING,
},
{ sequelize, modelName: 'products' },
);
User.hasMany(Product);
Product.belongsTo(User);
(async function test() {
try {
await sequelize.sync({ force: true });
// seed
await User.create(
{
email: 'example#gmail.com',
products: [{ name: 'apple' }, { name: 'amd' }],
},
{ include: [Product] },
);
// add another two products for this user
const SomeID = 1;
const productobj = [{ name: 'nvidia' }, { name: 'intel' }];
const productModels = await Product.bulkCreate(productobj);
const userObj = await User.findOne({ where: { id: SomeID } });
await userObj.addProducts(productModels);
} catch (error) {
console.log(error);
} finally {
await sequelize.close();
}
})();
data row in the database:
=# select * from users;
id | email
----+-------------------
1 | example#gmail.com
(1 row)
node-sequelize-examples=# select * from products;
id | name | userId
----+--------+--------
1 | apple | 1
2 | amd | 1
3 | nvidia | 1
4 | intel | 1
(4 rows)
NOTE: These methods only accept target model(s) as their parameter, NOT a plain javascript object or array of objects. You need to bulkCreate the products. Then, use userModel.addProducts(productModels) to associate these products to this user

Answer 2

It seems this is not supported as yet (although requested since 2015). We have a few options to workaround:
If your model definitions allow it, you can do as with slideshowp2's answer: bulkCreate the products, and then assign them to the user. This won't work if you are allowing nulls on the customerId column (which is probably not a good idea).
If you know the userId, you can include this id in each product item to be created, then use Products.bulkCreate(). This will work.
Create every product individually against the user. There's various ways of doing this eg something like
Promise.all(
productArray.map((prod) => {
return user.createProduct(prod)
}))