(PHP 5, PHP 7, PHP 8)
PHP と MySQL データベースの間の接続を表します。
$hostname = null,$username = null,$password = null,$database = null,$port = null,$socket = null$username, #[\SensitiveParameter] string $password, ?string $database): bool$hostname = null,$username = null,$password = null,$database = null,$port = null,$socket = null&$read,&$error,&$reject,$seconds,$microseconds = 0$hostname = null,$username = null,$password = null,$database = null,$port = null,$socket = null,$flags = 0