database class

<?php
 
class DB {
 
	//connection variables
	protected $dbhost = 'localhost';
	protected $dbuser = 'root';
	protected $dbpass = '';
	protected $dbname = 'database';
 
	//normal global resources
	protected $db = null;
	protected static $instance = null;
 
	/**
	 * Singleton pattern for instantiating the DB class
	 */
	public static function GetInstance()
	{
		if(!self::$instance)
		{
			self::$instance = new DB;
		}
		return self::$instance;
	}
 
	protected function __construct()
	{
		if(($db = @mysql_connect($this->dbhost, $this->dbuser, $this->dbpass)) === false)
		{
			trigger_error('There was an error connecting to the server.');
			exit;
		}
 
		if((@mysql_select_db($this->dbname, $db)) === false)
		{
			trigger_error('There was an error selecting the database.');
			exit;
		}
		$this->db = $db;
	}
 
	/**
	 * simple method for sanitizing SQL query strings.
	 */
	public function Clean($string)
	{
		if(get_magic_quotes_gpc())
		{
			$string = stripslashes($string);
		}
		return mysql_real_escape_string($string);
	}
 
	/**
	 * DB class method call to the Query child class.
	 * SELECT queries only
	 * Returns number of rows affected.
	 */
	public function Query($statement)
	{
		return new Query($statement, $this->db);
	}
 
	/**
	 * DB class method call to the Execute child class.
	 * INSERT/UPDATE/DELETE queries only
	 * Returns number of rows affected.
	 */
	public function Execute($statement)
	{
		return new Execute($statement, $this->db);
	}
 
	/**
	 * Used to get the last inserted record
	 */
	public function InsertID()
	{
		return mysql_insert_id($this->link);
	}
 
	public function __destruct()
	{
		@mysql_close($this->db);
	}
 
}
 
/**
 * These are separate classes for the reason that I would like
 * to be able to edit them with as little distruption to the 
 * flow of the parent class as possible. 
 */
 
/**
 * Query child class. Used for running SELECT queries.
 * Called exclusively by the DB parent class in the Query method
 */
class Query
{
	protected $result;
 
	public function __construct($statement, $link)
	{
		if(($this->result = mysql_query($statement, $link)) === false)
		{
			trigger_error('There was an error in processing the Query method: '. mysql_error());
			exit;
		}
	}
 
	/**
	 * I dont really like how this class is going so far. its almost
	 * emulating the regular set of mysql_fetch_*() functions.
	 *
	 * So, im going to try and implement some sort of method where
	 * i can specify the fetch action as an argument.
	 * EG. $result = $db->Query($query)->Fetch('object', 'class');
	 * Or $arr = $db->Query($query)->Fetch('assoc');
	 */
	public function Get($method, $class = null)
	{	
		$sql_magic = "mysql_fetch_".$method;
		if(isset($class))
		{
			return @$sql_magic($this->result, $class);
		} else {
			return @$sql_magic($this->result);
		}
	}
 
	public function NumRows()
	{
		return @mysql_num_rows($this->link);
	}
 
	public function __destruct()
	{
		@mysql_free_result($this->result);
	}
}
 
/**
 * Execute child class. Used for running INSERT/UPDATE/DELETE queries.
 * Called exclusively by the DB parent class in the Execute method
 */
class Execute
{
	public function __construct($statement, $link)
	{
		if((@mysql_query($statement, $link)) == false)
		{
			trigger_error('There was an error processing the Execute method: '. mysql_error());
			exit;
		}
		return @mysql_affected_rows($link);
	}
}
 
class Paginate
{
	/**
	 * Adding this so that I can have pagination included in the class
	 * 
	 * Its gonna be a bitch though.
	 */
}
 
?>