<?php


class Database {

    private $link;

    public function __counstruct() {
        $this->connect();
    }

    private function connect() {
        $user = 'animals';
        $pass = '****';
        $host='localhost';
        $db_name='animals';
        $dsn = "mysql:host=$host;dbname=$db_name";

        $this->link = new PDO($dsn, $user, $pass);

        return $this;
    }

    public function execute($sql) {
        $sth = $this->link->prepare($sql);

        return $sth->execute();
    }

    public function query($sql) {

        $sth = $this->link->prepare($sql);

        $sth->execute();

        $result = $sth->fetchAll(PDO::FETCH_ASSOC);

        return $result;
    }
}

$db = new Database();


?>

<?php

require('db.php');

$users = $db->query("SELECT * FROM 'animals'");
var_dump($users);

?>