Node + Knex code to create postgres tables for darklyrics data

createTables.js

/*
	1st create database:

	-go into the interactive interpreter 
			psql postgres

	Here we're creating:
		1. a databased called 'darklyrics'
		2. a user 'darklyricsuser'
		3. with password 'darklyricspassword'

	Then giving the newly created user privileges on the database.

	You can copy and paste these three lines directly into the psql interpreter:

		CREATE DATABASE darklyrics;
		CREATE USER darklyricsuser WITH ENCRYPTED PASSWORD 'darklyricspassword';
		GRANT ALL PRIVILEGES ON DATABASE darklyrics TO darklyricsuser;


	******DATABASE CREDENTIALS SHOULD GO IN A SEPARATE CONFIG FILE LIKE WITH THE 
		GOOGLE API KEY, BUT THIS CODE IS JUST FOR TESTING FOR NOW******

	Now we can connect to the database with knex.
  
  Install it globally and also into your project:
  
    npm install -g knex
    npm install knex --save
  
  Then run this command: 
  
    knex init
*/


/*
//two ways to connect...this commented one, or the one right below

const knex = require('knex')({
  client: 'pg',
  connection: {
    host : '127.0.0.1',
    user : 'darklyricsuser',
    password : 'darklyricspassword',
    database : 'darklyrics'
  }
});

*/

//second way to connect
const knex = require('knex')({
  client: 'pg',
  connection: 'postgresql://darklyricsuser:darklyricspassword@localhost/darklyrics',
});


async function createBandsTable(){
	return knex.schema.hasTable('bands')
			.then(function(exists) {
				if (!exists) {
				    return knex.schema.createTable('bands', function(table) {
					table.increments('id').primary();
					table.string('name');
					table.string('url');
				    });
				 }
			});
}


async function createAlbumsTable(){
	return knex.schema.hasTable('albums')
			.then(function(exists) {
				if (!exists) {
				    return knex.schema.createTable('albums', function(table) {
					table.increments('id').primary();
					table.string('name');
					table.string('type');
					table.string('year')
					table.integer('band_id').unsigned().notNullable()
					table.foreign('band_id').references('id').inTable('bands').onDelete("CASCADE");
					});
				  }
			});
}


async function createSongsTable(){
	return knex.schema.hasTable('songs')
			.then(function(exists) {
				if (!exists) {
				    return knex.schema.createTable('songs', function(table) {
					table.increments('id').primary();
					table.string('name');
					table.string('url');
					//table.string('translation')
					//table.string('language')//original language
					//any other data related to the translation
					table.integer('album_id').unsigned().notNullable()
					table.foreign('album_id').references('id').inTable('albums').onDelete("CASCADE");
					});
				  }
			})
}


async function createTables(){
	await createBandsTable();
	await createAlbumsTable();
	await createSongsTable();
	knex.destroy();
}


createTables();