echochio

//mysql基本連線方式
mysql_connect('localhost','root','password');
mysql_select_db('mydb');
mysql_query("SET NAMES 'utf8'");
$sql = "SELECT * FROM `user` WHERE name = 'sam'";
$result = mysql_query($sql);
if($result != false)
    while($row = mysql_fetch_object($result)){
        echo $row->name.'<br/>';
    }
}

//////////////  變成建構式
class db{

    public $host = 'localhost';
    public $username = 'root';
    public $password = 'password';
    public $database = 'mydb';

    function __construct($keyin){
        $this->key1 =$keyin;
        $this->sql_connect();
        $this->sql_database();
        $this->set_db_encode($key1);
    }

    function sql_connect(){
        return @mysql_connect($this->host,$this->username,$this->password);
    }

    function sql_database(){
        return @mysql_select_db($this->database);
    }

    function set_db_encode($key2){
        $this->key3 =$key2;
        return mysql_query($key3);
    }

}
$db = new db("SET NAMES 'utf8'");

//////////////////

class db{

    public $host = 'localhost';
    public $username = 'root';
    public $password = 'password';
    public $database = 'mydb';
    public $result;

    function __construct(){
        $this->sql_connect();
        $this->sql_database();
        $this->set_db_encode();
    }

    function sql_connect(){
        return @mysql_connect($this->host,$this->username,$this->password);
    }

    function sql_database(){
        return @mysql_select_db($this->database);
    }

    function set_db_encode(){
        return mysql_query("SET NAMES 'utf8'");
    }

    function query($sql_string){
        $result = mysql_query($sql_string);
        $query = new db_query($result);
        return $query;
    }

}

class db_query{
        
    private $result;
    
    function __construct($result){
        $this->result = $result;
    }

    function result(){
        $query = array();
        if($this->result != false){
            while($row = mysql_fetch_object($this->result)){
                $query[] = $row;
            }
            return $query;
        }
        return false;
    }

}
$db = new db();
$query = $db->query("SELECT * FROM `user` WHERE name = 'sam'"); // 如同 $query = new db_query 一般
foreach($query->result() as $row){
    echo $row->name.'<br/>';
}

//clase db --> opne db --> db_query