$host = 'db-sv39.cloudfree.ne.jp';
$user = '';
$pass = '';
$db = '';
$mysqli = new mysqli($host,$user,$pass,$db);
if (!$mysqli) {
exit('接続失敗です。'.mysql_error());
}

$close_flag = $mysqli->close();
if ($close_flag){
print('<p>切断に成功しました。</p>');
}

Fatal error: Uncaught mysqli_sql_exception: Host 'sv39.cloudfree.ne.jp' is not allowed to connect to this MariaDB server in /home/nennneko5787/nennneko5787.cloudfree.jp/public_html/blog/index.php:153 Stack trace: #0 /home/nennneko5787/nennneko5787.cloudfree.jp/public_html/blog/index.php(153): mysqli->__construct('db-sv39.cloudfr...', 'nennneko5787_ad...', 'quN2Uit6nWqLcW', 'nennneko5787_bl...') #1 {main} thrown in /home/nennneko5787/nennneko5787.cloudfree.jp/public_html/blog/index.php on line 153