create simple sequelize model

A few days ago, I started trying to figure out Sequelize, a promise-based ORM for NodeJS. I have always been a fan of JavaScript; it was the first programming language I started studying when I was only 15, along with — surprise, surprise — HTML5 and CSS3.

Suffice to say, I wanted to try and find the best ORM solution for NodeJS. After all, C# has Entity Framework and Java has Hibernate, so it was ripe time to find one for Node as well. I made my first search and found Sequelize to have around 250,000 downloads per week on npm. Not bad…

I started reading the documentation with its Getting Started section. It looked easy and fun, the code flowing out of me like a rivulet in spring, but then I arrived at a point where all my attempts just snagged on a barb in the documentation. I couldn’t for the life of me create a foreign key constraint

Sequelize is a promise-based ORM for Node.js. Sequelize is easy to learn and has dozens of cool features like synchronization, association, validation, etc. It also has support for PostgreSQL, MySQL, MariaDB, SQLite, and MSSQL. I am assuming you have some form of SQL database service started on your machine. I am currently using MySQL.

const routes = require("express").Router(); const restoController = require("../controller/restaurantcontroller"); routes.get("/", (req, res) => { res.render("home"); }); routes.get("/restaurants", restoController.viewallResto_get);

isFree: { type:DataTypes.BOOLEAN, validate: { isUnique: function(value, cb){ console.log(this._previousDataValues) if (this._previousDataValues.isFree == true){ throw new Error ('You must keep your promise to treat everyone') } else { cb() } } } hooks: { beforeBulkDestroy: (user, options, cb) => { if (user.where.participants > 0){ throw new Error (`Sorry, event, ${user.where.participants} people already confirmed to come`) } else { cb() } } } Schedule.prototype.getAvailableSeat = () =>{ let result = this.maxParticipants - this.participants return result };

Now, it should work, and of course the result will be an empty array because there is nothing in our database yet.

Let’s instead create a function that accepts an object category and an array of object products. We want this function to create a new row in the categories table in our PostgreSQL database with the new category object, while also creating new rows in the products table for each product object in the product array. Of course, this method should be called when every product in the array corresponds to the category object that is being passed.