PHP - Using classes to fetch user info - php

Question

Assume the connection to the database and all references to tables and cells is correct... how could I get something like this working?
class User
{
private $_display;
private $_email;
public function __construct($username)
{
$fetch_user = mysql_query("SELECT * FROM `registered_users` WHERE `user_name`='$username'");
$fetch_user = mysql_fetch_array($fetch_user);
$this->_display = $fetch_user['user_display'];
$this->_email = $fetch_user['user_email'];
}
}
$person1 = new User('username');
echo "Information: " . print_r($person1, TRUE);
the problem is it returns nothing. Doesn't thrown an error or anything when debugged. Is it viable method though? :S

Answer 1

Here is roughly what I would do:
<?php
class User{
private $username;
private $data;
public function __construct($username){
$this->username = $username;
if($this->valid_username()){
$this->load();
}
}
private function load(){
// Let's pretend you have a global $db object.
global $db;
$this->data = $db->query('SELECT * FROM registered_users WHERE user_name=:username', array(':username'=>$this->username))->execute()->fetchAll();
}
public function save(){
// Save $this->data here.
}
/**
* PHP Magic Getter
*/
public function __get($var){
return $this->data[$var];
}
/**
* PHP Magic Setter
*/
public function __set($var, $val){
$this->data[$var] = $val;
}
private function valid_username(){
//check $this->username for validness.
}
// This lets you use the object as a string.
public function __toString(){
return $this->data['user_name'];
}
}
How to use:
<?php
$user = new User('donutdan');
echo $user->name; //will echo 'dan'
$user->name = 'bob';
$user->save(); // will save 'bob' to the database