<?phpheader("Content-type:text/html;charset=utf-8");$server="localhost";$username="root";$password="123456";echo ‘开始mysql数据库连接．<br><br><br>‘;$mysqli=new mysqli($server,$username,$password);if($mysqli){    echo ‘连接mysql数据库成功．<br>‘;    echo ‘You can use \‘new mysqli()\‘ to connect.<br><br>‘;    $mysqli->close();}if($con1= mysqli_connect($server,$username,$password)){    echo ‘连接mysql数据库成功．<br>‘;    echo ‘You can use mysqli_connect() to connect.<br><br>‘;    mysqli_close($con1);}if($con2=mysql_connect($server,$username,$password)) {    echo ‘连接mysql数据库成功．<br>‘;     echo ‘You can use mysql_connect() to connect.<br><br>‘;         mysql_close($con2);}else{    die(‘连接mysql数据库失败：‘ . mysql_error());}echo ‘<br><br><br>‘;echo ‘关闭mysql数据库连接．‘;?>