compact-sequelize

compact-sequelize

npm install compact-sequelize

Overview

The goal of compact-sequelize is to make the objects returned by the sequelize ORM more readable and manageable. And secondly apply the toJSON method recursively.

We often want to get a single field from linked tables. Although sequelize allows us to achieve this, the resulting structure has unnecessary complexity.

As an example we will get orders and their details. For each order, the user (email), product detail, brand (name), gender (name), and product categories (name).

The corresponging sequelize code

Order.findAll({
  include: [
    { model: User, attributes: ["email"] },
    {
      model: OrderDetail,
      include: [
        {
          model: Product,
          include: { model: Brand, attributes: ["name"] },
          include: { model: Gender, attributes: ["name"] },
          include: { model: Category, attributes: ["name"] },
        },
        { model: Size, attributes: ["name"] }
      ]
    }
  ],
})

and we get a json like this:

[{
  "id": 42,
  "date": "2022-01-27T07:54:02.571Z",
  "status": "carrito",
  "userId": 12,
  "user": {
    "email": "andres@sportbase.com"
  },
  "OrderDetails": [
    {
      "id": 197,
      "price": 10999,
      "quantity": 2,
      "orderId": 42,
      "productId": "c2fcdddd-2ea4-465a-939a-63d91bb60aa0",
      "sizeId": 12,
      "product": {
        "id": "c2fcdddd-2ea4-465a-939a-63d91bb60aa0",
        "name": "Adidas jacket Firebird",
        "price": 10999,
        "genderId": 2,
        "brandId": 1,
        "brand": {
          "name": "Adidas"
        },
        "gender": {
          "name": "Woman"
        },
        "categories": [
          {
            "name": "jacket",
            "product_category": {
              "createdAt": "2022-01-20T02:05:12.939Z",
              "updatedAt": "2022-01-20T02:05:12.939Z",
              "productId": "c2fcdddd-2ea4-465a-939a-63d91bb60aa0",
              "categoryId": 5
            }
          },
          {
            "name": "sportswear",
            "product_category": {
              "createdAt": "2022-01-20T02:05:12.939Z",
              "updatedAt": "2022-01-20T02:05:12.939Z",
              "productId": "c2fcdddd-2ea4-465a-939a-63d91bb60aa0",
              "categoryId": 9
            }
          }
        ]
      },
      "size": {
        "name": "XL"
      }
    }
  ]
}]

compact-sequelize is particularly useful in many-to-many relationships such as product and category relationships.

Finally we apply the compact function to the sequelize object/array.

const { compact } = require('compact-sequelize');
const { Order, User, OrderDetail, Size, Product, Gender, Brand, Category } = require("./src/db.js");

const getOrders = async () => {

  const orders = compact(await Order.findAll({
    include: [
      { model: User, attributes: ["email"] },
      {
        model: OrderDetail,
        include: [
          {
            model: Product,
            include: { model: Gender, attributes: ["name"] },
            include: { model: Brand, attributes: ["name"] },
            include: { model: Category, attributes: ["name"] }
          },
          { model: Size, attributes: ["name"] }
        ]
      }
    ],
  }));

  return orders;
}

Next we get a more concise object

{
  "id": 42,
  "date": "2022-01-27T07:54:02.571Z",
  "userId": 12,
  "user": "andres@sportbase.com",
  "OrderDetails": [
    {
      "id": 197,
      "price": 10999,
      "quantity": 2,
      "orderId": 42,
      "productId": "c2fcdddd-2ea4-465a-939a-63d91bb60aa0",
      "sizeId": 12,
      "product": {
        "id": "c2fcdddd-2ea4-465a-939a-63d91bb60aa0",
        "name": "Adidas jacket Firebird",
        "price": 10999,
        "genderId": 2,
        "brandId": 1,
        "brand": "Adidas",
        "gender": "Woman",
        "categories": [
          "jacket",
          "sportswear"
        ]
      },
      "size": "XL"
    }
  ]
}