Object Oriented Database Connection Quickstart

quickstart.php

<?php
define('DB_NAME', 'zip');
 
/** MySQL database username */
define('DB_USER', '*****');
 
/** MySQL database password */
define('DB_PASSWORD', '*****');
 
/** MySQL hostname */
define('DB_HOST', 'localhost');
$db         = new db();
$zip        = new zip($db);

$zip->all();

class db {
    public $conn;
 
    public function __construct () {
        try
        {
            $this->conn = new PDO('mysql:host=' . DB_HOST . ';dbname=' . DB_NAME, DB_USER, DB_PASSWORD);
            $this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        catch(PDOException $e)
        {
            echo 'ERROR: ' . $e->getMessage();
        }
    }
}
class zip {
    public $db;
 
    function __construct($db) {
        //print_r($db);
        $this->db = $db;
    }
    function all()
    {
        //FETCHING
        try
        {
            $stmt       = $this->db->conn->prepare('SELECT * FROM `cities_extended`');
            $stmt->execute();
            $result     = $stmt->fetchAll();
            $count      = count($result);
            if($count)
            {
                echo $count . ' rows returned...';
            }
            else
            {
                echo "No rows returned...";
            }
        }
        catch(PDOException $e)
        {
            echo 'ERROR: ' . $e->getMessage();
        }
    }
}
?>