从联系表7写入Bluehost上的数据库

Question

嗨，有人可以帮我吗？我是PHP新手，正在尝试将联系表单的输出内容写入数据库-我的代码不正确，有人可以帮忙吗？

add_action('wpcf7_before_send_mail', 'save_form');

function save_form($wpcf7) {

/* For connecting to database */
$dbuser = "DBUserName";
$dbpass = "DBPass";
$dbhost = "localhost";
$dbname = "DBName";

// Connect to server and select database.
$db = mysqli_connect($dbhost, $dbuser, $dbpass) or die("cannot 
connect");
mysqli_select_db($db, $dbname) or die("cannot select DB");

$form_to_DB = WPCF7_Submission::get_instance();
if ( $form_to_DB ) 
    $formData = $form_to_DB->get_posted_data();
$title = $formData['title'];

$mydb->insert( 'DBTableName', array( 'title' =>$title ), array( '%s' ) 
);

if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
}
}