Express-Sequelize Tutorial

please note: I am still working on the code in this repo. Things might not all be working correctly yet.

1. Local Setup
2. Database
3. NPM Scripts
4. More Information: See Wiki (coming soon)

Local Setup

1. npm run setup -> installs NPM packages and creates the .env file (might not work on Windows, sorry); if it doesn't work for you, then just manually copy the sample-env file and rename it .env
2. Fill in the .env file according to your local setup
3. Make sure Postgres is running on your local machine
4. Set up the db:

• Run this if you need to create the DB: npm run db:create
• npm run db:seed

5. npm start to run the main Express and Swagger servers

• Access the API at localhost:3000/api/v1/[endpoint]
• Access the Swagger API docs at localhost:3001/api-docs (JSON docs) or localhost:3001/api-ui (interactive UI)

Database

We interface with Postgres using the Sequelize library. Sequelize comes in two parts: the library we use to build models and connect to Postgres; and the CLI for functions like seeding the database and running migrations.

Creating New Models

1. Use the Sequelize CLI command (change the attributes as needed; if you need to add or change anything, no worries, you can do it later):

npx sequelize-cli model:create --name users --attributes is_active:boolean,first_name:string,last_name:string,email:string,university_id:string,api_token:string,type:string,avatar_url:string,is_fake:boolean

That command will create a model file called users.js inside of db/models as well as a migrations file called [timestamp]-create-user.js inside of db/migrations.

2. If you need to change anything, you can either update the migration file and re-run the migration or create and run a new migration. Either way, you will have to update the related model file with the changes.

Aside: Read more about data validation in Sequelize

Creating New Migrations

When you need to update the database (tables, columns, etc.), Sequelize has a nice interface to take care of the migrations for you.

npx sequelize-cli migration:create --name add-email-to-user

Make sure you fill in the up and down functions just in case you have to revert the changes.

Undo-ing Migrations

You can use db:migrate:undo, this command will revert most recent migration.

npx sequelize-cli db:migrate:undo

You can revert back to initial state by undoing all migrations with db:migrate:undo:all command. You can also revert back to a specific migration by passing its name in --to option.

npx sequelize-cli db:migrate:undo:all --to XXXXXXXXXXXXXX-create-posts.js

Seeding the Database

npx sequelize-cli seed:generate --name users

npm run db:seed

This will create a seeding file similar to migration files named, [timestamp]-users.js.

You can use something like Mockaroo to make mock data and paste it into the seed file.

Undo-ing Seeds

If you wish to undo most recent seed:

npx sequelize-cli db:seed:undo

If you wish to undo a specific seed:

npx sequelize-cli db:seed:undo --seed name-of-seed-as-in-data

If you wish to undo all seeds:

npx sequelize-cli db:seed:undo:all

NPM Scripts

npm test

Runs tests - using Jest - from the __tests__ folder.

npm run lint

Runs eslint.

npm run lint:fix

Corrects common linting errors.

npm start

Runs Express server.

npm run db:create

Creates the database.

npm run db:seed

Seeds the database from files in db/seeders.

npm run db:migrate

Runs migrations from files in db/migrations.

npm run db:clean

Removes (and truncates) all data from database tables.