一個php與mysql連接類

<?php 
/**
* desc：mysql操作类
* filename:db.class.php
* by bbs.it-home.org
*/
 
Class db
{
//数据库配置信息
private $Host='localhost';
private $UserName='root';
private $Password='';
private $DbName='dbname';
//根据自己的实际情况修改

public  $link;
public $query;
public $last_error;

function __construct()
{    
   $this->Connect();
}
function __destruct()
{
   $this->Close();
}
private function Connect()
{
   //数据库连接
   $this->link=mysql_connect($this->Host,$this->UserName,$this->Password) or die("Error Connect to DB");
   $this->SetError(mysql_error());
   //select db ...
   mysql_select_db($this->DbName) ;//or die("Error Select DB");
   $this->SetError(mysql_error());
}

public function query($query)
{
 //mysql查询
 $this->query=mysql_query($query,$this->link);
 $this->SetError(mysql_error());
}
    
public function assoc()
{
   //mysql_fetch_assoc :
   return mysql_fetch_assoc($this->query);
   $this->SetError(mysql_error());
}

public function num()
{
   //mysql_num_rows:
   return mysql_num_rows($this->query);
   $this->SetError(mysql_error());
}
    
public function result($index=0)
{
   //mysql_result : 
   return mysql_result($this->query,$index);
   $this->SetError(mysql_error());
}
    
private function SetError($error)
{
  $this->last_error=$error;
}

public function ShowError()
{
   return $this->last_error;
}

private function Close()
{
  mysql_close($this->link);
}
}
?>

<?php
// include class : 
require_once "db.class.php"; 

//creat a db object 
$con=new db; 

//run the query: 
$con->query("select * from table "); 

//get number of result 
echo $con->num() . PHP_EOL; 

//get result 
echo $con->result(/* $index */) . PHP_EOL; 

//get all result 
while($row=$con->assoc()) var_dump($row);