php对mysql的增删改查

<?php

   class SqlTool{

    private $conn;
private $host="localhost";
private $user="root";
private $password="1234";
private $db="test";

function SqlTool(){
$this->conn=mysql_connect($this->host,$this->user,$this->password);
if(!$this->conn){
die("连接数据库失败".mysql_error());
}
mysql_select_db($this->db,$this->conn);
mysql_query("set names utf8");

}
//完成select

     function execute_dql($sql){
$res=mysql_query($sql)or die(mysql_error());

return $res;
}

//完成update delete insert 
function execute_dml($sql){
$b=mysql_query($sql,$this->conn);
if(!$b){
return 0;//失败
}else{
if(mysql_affected_rows($this->conn)>0){
return 1;//表示成功
}else{
return 2;//表示没有行数影响
}

}

}

}

?>