How do I substract/add currency to balance with quick.db? - discord.js

Question

The bot says that I robbed someone but does not add/substract the currency from neither of the users.
Another issue I found is that I can rob myself.
Code I used:
const Discord = require("discord.js");
const db = require("quick.db");
const ms = require("parse-ms");
module.exports.run = async (bot, message, args) => {
if(!message.content.startsWith('db!'))return;
let user = message.mentions.members.first()
let targetuser = await db.fetch(`money_${message.guild.id}_${user.id}`)
let author = await db.fetch(`rob_${message.guild.id}_${user.id}`)
let author2 = await db.fetch(`money_${message.guild.id}_${user.id}`)
let timeout = 600000;
if (author !== null && timeout - (Date.now() - author) > 0) {
let time = ms(timeout - (Date.now() - author));
let timeEmbed = new Discord.RichEmbed()
.setColor("#FFFFFF")
.setDescription(`❌ You have already robbed someone\n\nTry again in ${time.minutes}m ${time.seconds}s `);
message.channel.send(timeEmbed)
} else {
let moneyEmbed = new Discord.RichEmbed()
.setColor("#FFFFFF")
.setDescription(`❌ You need atleast 200 dabloons in your wallet to rob someone`);
if (author2 < 200) {
return message.channel.send(moneyEmbed)
}
let moneyEmbed2 = new Discord.RichEmbed()
.setColor("#FFFFFF")
.setDescription(`❌ ${user.user.username} does not have anything you can rob`);
if (targetuser < 0) {
return message.channel.send(moneyEmbed2)
}
let vip = await db.fetch(`bronze_${user.id}`)
if(vip === true) random = Math.floor(Math.random() * 200) + 1;
if (vip === null) random = Math.floor(Math.random() * 100) + 1;
let embed = new Discord.RichEmbed()
.setDescription(`✔️ You robbed ${user} and got away with ${random} dabloons!`)
.setColor("#FFFFFF")
message.channel.send(embed)
db.subtract(`money_${message.guild.id}_${user.id}`, random)
db.add(`money_${message.guild.id}_${user.id}`, random)
db.set(`rob_${message.guild.id}_${user.id}`, Date.now())
};
}
module.exports.help = {
name:"rob",
aliases: [""]
}
I tried using code from other people, but the code I used did not work and just broke the bot

Answer 1

To solve the db issue, you can see Elitezen's comment
To solve the issue where you can rob yourself,
you can simply check if the person getting robbed is the author of the message
if(message.mentions.members.first().id === message.member.id) return message.channel.send(errorEmbed)
Also, this is a super outdated version of discord.js and is highly recommended to update.