是的！您需要删除任何HTML在connect_db.php文件。我建议存储变量在该文件中检查，如果你的连接成功。例如：

Yep! You need to remove any HTML in the connect_db.php file. I recommend storing a variable in that file checking if your connection was successful. For example:

connect_db.php

$isConnected = false;
$dbError = "";
if ($dbc=mysqli_connect('localhost','*****','*****','ff') {
    $isConnected = true;
} else {
    $dbError = mysqli_connect_error();
}

等文件

require("connect_db.php");

if($isConnected) {
    //DO ALL YO STUFF!!
} else {
    //HANDLE THE ERROR AS YOU LIKE, LIKE PRINTING IT OUT
    echo $dbError;
}

这样做可以让你如果无法连接，所以你可以得体的处理失败的连接处理数据库逻辑文件。

Doing this will allow you to handle the DB logic in your files if it fails to connect so you may handle failed connections gracefully.