db-connection.php

<?php
/**
* Author: Lukas Kusk Gjetting
*/

$db = new Databasing(true); // Change parameter to correspond to whether or not I'm at home right now.

class Databasing {
    protected $mysqli;

    public function __construct($athome) {

        $this->mysqli = $this->getConnected($athome);

    }

    function getCategories(){
        $query = "SELECT * FROM `categories`";

        $result = $this->mysqli->query($query);
        $array = $result->fetch_all();

        return $array;
    }

    function getExcercises($cat){
        $query = "SELECT * FROM `excercises` WHERE `cat_id` = " . $cat;

        $result = $this->mysqli->query($query);
        $array = $result->fetch_all();

        return $array;
    }

    function getConnected($athome) {

        if($athome){ // If I'm at home, use the XAMPP MySQL-credentials
            $host = "localhost";
            $db = "database";
            $user = "root";
            $pass = "";
        }else{      // If not, use the UnoEuro-ones
            $host = "mysql38.unoeuro.com";
            $db = "thedatabase_1";
            $user = "lukasgjetting";
            $pass = "password";
        }
        $mysqli = new mysqli($host, $user, $pass, $db);

        if($mysqli->connect_error) // Couldn't connect! Maybe I haven't changed the $athome parameter?
            die('Connect Error (' . mysqli_connect_errno() . ') '. mysqli_connect_error());

        return $mysqli;
    }
}