PHP OOP and PDO - php

Question

My first real foray into using PHP OOP and PDO extensively. I have finally gotten the script to work, but as you notice in order to do it I had to move the PDO connect into the login function - originally it was just in the __construct(). I do not want to have to open a new PDO connect and this is sloppy. How can I maintain the same connection throughout the whole class?
<?php
class user{
public $id;
public $name;
public $email;
private $password;
public function __construct() {
$DBH = new PDO("mysql:host=HOST;dbname=DB", "USER", "PASS");
$DBH->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
public function login($email,$password,$type){
$DBH = new PDO("mysql:host=HOST;dbname=DB", "USER", "PASS");
$DBH->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$password_hash = sha1($password);
try{
if ($type != "actives") {
throw new Exception("Type Handling Error");
}
$STH = $DBH->query("SELECT id, email, password FROM $type WHERE email='$email' AND password='$password_hash'");
$STH->setFetchMode(PDO::FETCH_ASSOC);
$row_count = $STH->rowCount();
$row = $STH->fetch();
if($row_count == 1){
session_start();
session_regenerate_id();
$_SESSION['id'] == $row[id];
return true;
}
else{
return false;
}
}
catch (Exception $e) {
echo $e->getMessage();
}
}
public function loggout(){
session_destroy();
setcookie(session_name(), session_id(), 1, '/');
}

Answer 1

Make the database handle a private member within the class:
class user
{
public $id;
public $name;
public $email;
private $password;
private $dbh;
public function __construct(PDO $dbh)
{
$this->dbh = $dbh;
}
public function login($email, $password, $type)
{
$dbh = $this->dbh;
...
}
Usage:
$pdo = new PDO("mysql:host=HOST;dbname=DB", "USER", "PASS");
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$user = new User($pdo);

Answer 2

Sooner or later, you may need the PDO connection object somewhere else in your code(outside your user object). Therefore,
I would suggest to use one class which will provide static method as below to get the PDO connection object everywhere you want.
class Database{
private static $datasource='mysql:host=HOST dbname=DB';
private static $username='USER';
private static $password='PASS';
private static $db;
//make the constructor private and empty so that no code will create an object of this class.
private function __construct(){}
//the main public function which will return the required PDO object
public static function getDB(){
if(!isset(self::$db)){
try{
self::$db=new PDO(self::$datasoure,self::$username,self::$password);
}
catch(PDOExceptin $e)
{
$error=$e->getMessage(); //variable $error can be used in the database_error.php file
//display database error file.
include('database_error.php');
exit();
}
}
return self::$db;
}
}
Then you can use the static method like below any time you want PDO connection
$conn=Database::getDB();

Answer 3

Use ceejayoz' proposal or add a global function which is responsible for establishing the database connection. The function is written as to connect to the database at most 1 time per HTTP request:
function getPDOConnection() {
// Thanks to the static-specifier, this variable will be initialized only once.
static $conn = new PDO("mysql:host=HOST;dbname=DB", "USER", "PASS");
return $conn;
}
This enables you to maintain the same connection in your whole application (but of course you don't have to use the function everywhere). Basically, this is a very simple application of the Singleton pattern. See the documentation of the static specifier/keyword and try to get familiar with the Singleton pattern.

Answer 4

Add your database connection as a parameter in the constructor, So you when you create a new instance from the user class it automatically runs across the instantiated object

Answer 5

The variable $DBH needs to be a member variable of your class.
Below private $password;, add private $DBH; and you're good to go with deleting the new-connection code from your login function.