asl-schema

Objection.js schema for licensing models.

• @asl/schema provides models for interacting with database records.

Usage

Install the package:

npm install @asl/schema --save-prod

Import as necessary:

const db = require('@asl/schema');
const models = db(settings.db);

Configuration

The service can be configured for local development by setting environment variables in a .env file.

The following environment variables are required:

• DATABASE_NAME - the name of your postgres database

Implementation

To facilitate database connection using postgres, migrations, and seeds we use knex.

To query the database, we use Objection.js ORM.

Property and column naming

Postgres is case-insensitive when it comes to table and column names, so the convention is to use snake_case in the database. However, we would prefer our model objects to use camelCase, so we need to map between the formats.

This can be done automatically by enabling knexSnakeCaseMappers, which allows us to use camelCase for all model properties, relations, and seed data. The only place the mapping is not performed is for migrations, where it would not make sense.

Migrations

To generate a new migration:

knex migrate:make <_migration-file-name_>

A migration file is generated with:

exports.up = function(knex, Promise) {

};

exports.down = function(knex, Promise) {

};

The migration goes within the body of the exports.up function.

To undo migration, use exports.down.

For existing examples, see the folder migrations.

To run the migrations:

npm run migrate

Note: this will run all migrations in the folder which have not already been performed. Previously executed migrations are stored in a special table called knex_migrations.

To rollback the migrations:

npm run rollback

For more information, see https://knexjs.org/#Migrations.

Database Seeding

To seed, or add initial test data to the database:

npm run seed