如何在php中连接mysql数据库

<必修php include 'vendor/autoload.php';

<必修php use Unirest\Request;

$host = 'localhost';
$user = 'root';
$password = 'password';
$database = 'database_name';

$connection = new <a style='color:#f60; text-decoration:underline;' href="https://www.php.cn/zt/15713.html" target="_blank">mysqli($host, $user, $password, $database);

if ($connection-&gt;connect_errno) {
    die("无奈衔接到 MySQL: (" . $connection-&gt;connect_errno . ") " . $connection-&gt;connect_error);
}

<必修php $sql = "SELECT * FROM users";
$result = $connection->query($sql);

if ($result-&gt;num_rows &gt; 0) {
    while ($row = $result-&gt;fetch_assoc()) {
        print_r($row);
    }
} else {
    echo "不功效。";
}

<选修php $connection->close();