val = 20;
//clone可以调用__clone()克隆即new出
一个新的的对象
//$obj_two = clone $obj_one;
$obj_two = instance::ge
Tinstance(
);
echo $obj_two->val;
echo '
';
var_dump($obj_one,$obj_two);
3306,'host' => 'localhost','username' => 'root','pass
WARD' => 'root','dbname' => 'instance','charset' => 'utf8'
);
private $link;
static $instance;
private function __clone()
{}
private function __construct()
{
$this->link = mysql_connect($this->arr['host'],$this->arr['username'],$this->arr['pass
WARD']) or die(mysql_error()
);
mysql_
SELEct_db($this->arr['dbname']) or die('db error'
);
mysql_set_charset($this->arr['charset']
);
}
static public function ge
Tinsance()
{
if(!isset(mysqldb::$instanc
E))
{
mysqldb::$instance = new self;
}
return mysqldb::$instance;
}
public function query($sql)
{
if($res = mysql_query($sql))
{
return $res;
}return
false;
}
//fetch one
public function get_one($sql)
{
$res = $this->query($sql
);
if($result = mysql_fetch_row($res))
{
return $
result[0];
}
}
//fetch row
public function get_row($sql)
{
$res = $this->query($sql
);
if($result = mysql_fetch_assoc($res))
{
return $result;
}
return
false;
}
//fetch all
public function get_all($sql)
{
$res = $this->query($sql
);
$arr = array(
);
while($result = mysql_fetch_assoc($res))
{
$arr[] = $result;
}
return $arr;
}
}
$mysql = mysqldb::ge
Tinsance(
);
