php如何访问mysql

<?php $servername = "localhost";
$username = "root";
$password = "";
$dbname = "myDB";

// 创建连接
$conn = new <a style=\'color:#f60; text-decoration:underline;\' href="https://www.php.cn/zt/15713.html" target="_blank">mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn-&gt;connect_error) {
    die("连接失败: " . $conn-&gt;connect_error);
}
?&gt;