DAL for SAE

gistfile1.php

<?php
/*
Data Access Layer for FansWall(http://fanswall.sinaapp.com)
Author: Shiny Zhu(http://t.sina.com.cn/shinyzhu)
*/

class DAL{
    private $server, $username, $password, $db;
    private $link;
    private $result;
    
    public function __construct($server, $username, $password, $db){
        $this->server = $server;
        $this->username = $username;
        $this->password = $password;
        $this->db = $db;
        
        $this->connect();
    }
    
    function __destruct(){
        if(!$this->result) mysql_free_result($this->result);
        mysql_close($this->link);
    }
    
    private function connect(){
        $this->link = mysql_connect($this->server, $this->username, $this->password) or die("Can NOT connect: " . mysql_error());
        mysql_select_db($this->db, $this->link) or die("Can NOT select the database '" . $this->db . "'.");
    }
    
    public function query($sql){
        if($this->result = mysql_query($sql, $this->link) or die("Query failed: " . mysql_error())){
            return $this->result;
        }else{
            return false;
        }
    }
    
    public function fetch_array($result){
		return mysql_fetch_array($result);
    }
    
    public function fetch_first($sql){
		return mysql_fetch_array($this->query($sql));
    }
    
    public function num_rows($result){
        return mysql_num_rows($result);
    }
    
    public function update($sql){
        return $this->query($sql);
    }
    
    public function insert($sql){
        return $this->query($sql);
    }
    
	function get_last_id(){
		return mysql_insert_id();
	}
    
    public function __toString(){
        return "Database '". $this->db . "' from mysql server hosted at '" . $this->server . "'.";
    }
}
?>