Making a currency system with Quick.db

We will use Quick.db to store data this time. We will be making a currency system with Quick.db, which honestly isn't the best practice, but I'm doing it to demonstrate how use Quick.db. In my opinion, I think that Quick.db is easier to use than Sequelize.
We will be using async/await operators, so make sure you have a Node.js version that supports it.

Installation

npm i quick.db --save

yarn add quick.db

Using Quick.db

Quick.db doesn't require much configuration. All you need to do to use it is to require it:

const db = require('quick.db');

Creating an account

Each user who uses your bot needs an account. First, create a create command. Then, we check if the user already has an account by using Quick.db's db.has() function, and return if they do:

if(db.has(message.author.id)) {
  return message.channel.createMessage(`${message.author.mention}, you already have an account!`);
}

If the user doesn't have an account, let's be kind and give them $10:

db.add(`${message.author.id}.bal`, 10);

Just to be sure that it's added properly, let's fetch it:

const bal = db.get(`${message.author.id}.bal`);

Now, let's send a message to the user and tell him how much he has:

message.channel.createMessage(`Done! ${message.author.mention}, you now have ${bal}`);

There! We have created an account.

Force the user to create an account

If you want your user to create an account before doing anything else, you can add this after the following:

if (!message.content.startsWith(prefix) || message.author.bot) return;
const args = message.content.slice(prefix.length).trim().split(/ +/);
const commandName = args.shift().toLowerCase();
if (!db.has(message.author.id) && commandName != 'create') {
	return message.channel.createMessage(`${message.author.mention}, you don't have an account yet! Run \`${prefix}create\` to create one!`);
}

Making a `beg` command

We need a command to give the user money, so let's make a beg command. As usual, create a beg command file. You can get a random name just for fun, and let's use got for it. Run npm i got --save and add const got = require('got'); at the top of your file. Now, look for execute(...) in your file and replace it with async execute(...) if you haven't done so yet.
Fetch a random user profile and get the name from it:

const result = await got('https://randomuser.me/api/');
const person = JSON.parse(result.body);
const name = person.results[0].name.first + ' ' + person.results[0].name.last;

Calculate the amount of money the user should get:

const amount = Math.floor(Math.random() * 30) + 1;

and add it to the user's balance:

db.add(`${message.author.id}.bal`, amount);

Finally, tell the user how much he got:

message.channel.createMessage({
  embed: {
		title: name,
		description: `${message.author.mention}, you went begging and found ${amount}!`,
		footer: {
			text: '😏',
		},
	},
});

Making a shop

Most currency bots have a shop system. Let's make one, too! Create a shop command file.

Require Quick.db, and as you might not want to store the shop and user information together in the same table, let's create a new one:

// NOTE: Put this outside of your module.exports
const shop = new db.table('shop');

Add a couple of items:

// NOTE: Put this outside of your module.exports
const shop = new db.table('shop');
shop.set('🍪 Cookie.cost', 5);
shop.set('🍪 Cookie.type', 'collectable');
shop.set('🍪 Cookie.d', 'A random cookie found on the streets');

shop.set('☠ Poison.cost', 9000);
shop.set('☠ Poison.type', 'collectable');
shop.set('☠ Poison.d', 'Some cyanide that\'s only used for flexing');

shop.set('🍟 Fries.cost', 11);
shop.set('🍟 Fries.type', 'collectable');
shop.set('🍟 Fries.d', 'Some yummy fries from McDonald\'s');

shop.set('🔳 Emoji.cost', 1);
shop.set('🔳 Emoji.type', 'unsellable');
shop.set('🍪 Cookie.type', 'collectable');

shop.set('💵 Cash.cost', 100);
shop.set('💵 Cash.type', 'unbuyable');
shop.set('💵 Cash.d', 'Sell this for some quick cash');

shop.set('🎟 Ticket.cost', 30);
shop.set('🎟 Ticket.type', 'power-up');
shop.set('🎟 Ticket.d', 'Buy this scratch ticket and try your luck?');

Add the shop variable to your module.exports, so that it looks something like this:

module.exports = {
	name: 'shop',
	description: 'view the shop',
	args: false,
	shop,
	execute(message, args) {
      // ...
    }
};

NOTE

The following code is supposed to be put in execute(message, args)

First, we initialize an empty array for the embed fields and fetch all the items of the shop (which is returned in an array):

const shoplist = [];
const shopll = shop.all();

We then push the different items and their properties to the array shoplist:

for (let i = 0; i < shopll.length; i++) {
  const currentItem = {
    name: shopll[i].ID,
    value: `${shopll[i].data.d}\nCost: \`${shopll[i].data.cost}\` \n Type: \`${shopll[i].data.type}\` \n ID: \`${shopll[i].ID}\``,
	  inline: false,
  }
};
shoplist.push(currentItem);

Finally, we send it:

message.channel.createMessage({
	embed: {
		title: 'Shop',
        fields: shoplist,
		footer: {
			text: '💸',
		},
	},
});

A `buy` command

For this, we will need the package fuzzy-searchopen in new window. Proceed to install it:

npm i fuzzy-search --save

yarn add fuzzy-search

Now, create a buy command. Let's change some of the parameters so that your module.exports look something like the following:

module.exports = {
	name: 'buy',
	description: 'buy something',
	args: true,
	usage: '<item> <amount?>',
	execute(message, args) {
      // ...
    }
};

We need to require a couple of things, so add this at the top of the file:

const db = require('quick.db');
const { shop } = require('./shop.js');
const FuzzySearch = require('fuzzy-search');

Now, get the item and the amount the user wants to buy, and create a new fuzzy search (pardon me for the weird variable names):

const item = args[0];
const amt = parseInt(args[1]) || 1;
const shoop = shop.all();
const searcher = new FuzzySearch(shoop, ['ID']);

Create a try/catch block to handle errors:

try {
  
}
catch(e) {
  console.error(e);
}

NOTE

The following is to be placed inside the try {} block.

Now, get the search result, and in case you haven't noticed, there's and item type called unbuyables, which as you guessed, aren't buyable:

const result = searcher.search(item);
if(result[0].data.type == 'unbuyable') {
	return message.channel.createMessage(`${message.author.mention}, you cannot buy \`unbuyables\`!`);
}

Get the item cost, check if the user has enough money to buy the item(s), deduct the amount from his balance, and add the items to his inventory:

const res = parseInt(result[0].data.cost);
if(db.get(`${message.author.id}.bal`) < res * amt) return message.channel.createMessage('Hey you don\'t even have enough money LMAO');
db.subtract(`${message.author.id}.bal`, res * amt);
db.add(`${message.author.id}.inv.${result[0].ID}`, amt);

Finally, inform the author:

message.channel.createMessage(`${message.author.mention}, you succesfully bought **${amt} ${result[0].ID}(s)**`);

Tell the author if the item he requested for doesn't exist (add this to the catch(e) {} block):

catch(e) {
	console.warn(e);
	return message.channel.createMessage('Sorry, that item fails to exist. Could you try another one or type in the full name?');
}

The `inv` command

Since the user has items, he should be able to view them. This is what the inv command does; it shows the user's inventory. Here's the complete code for the file:

const db = require('quick.db');

module.exports = {
	name: 'inv',
	aliases: ['inventory'],
	description: 'view your inventory',
	args: false,
	execute(message, args, prefix) { 
		if(!db.has(`${message.author.id}.inv`)) {
			return message.channel.createMessage('Your inventory is empty. Type `' + prefix + 'shop` to view some items.');
		}
		const invdisp = [];
		const inv = db.get(`${message.author.id}.inv`);
		for(i in inv) {
			const str = `${inv[i]} ${i}(s) \n`;
			invdisp.push(str);
		}
		const invstr = invdisp.join('\n');
		message.channel.createMessage({
			embed: {
				title: `${message.author.username}'s inventory`,
				description: invstr,
			},
		});
	},
};

This is about the most basics for a currency bot, you can view an example in this GitHub repositoryopen in new window.

# Making a currency system with Quick.db

# Installation

# Using Quick.db

# Creating an account

# Force the user to create an account

# Making a beg command

# Making a shop

# A buy command

# The inv command