php+mysqli数据库连接的两种方式

$mysqli = new MySQLi("localhost","root","1233456");//默认的 MySQL的类，其属性与方法见手册
if($mysqli->connect_error){//connect_error为属性，报错
 die("数据库连接失败".$mysqli->connect_errno."--".$mysqli->connect_error);// connect_errno:错误编号
}
$mysqli->select_db("liuyan");//选择数据库
$mysqli->query("set names 'GBK'");

$conn = @mysqli_connect("localhost","root","123456") or die(mysqli_connect_error());
mysqli_select_db($conn,"liuyan") or die(mysqli_connect_error());//与mysql扩展库不同，这里数据库名写在后面，而且 $conn是必选的
mysqli_query($conn,"set names 'GBK'");//同上
?>