如何在PHP MySQL中确定状态和做事情？

<?php
// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = mysqli_connect($servername, $username, $password, $dbname);

// 检查连接是否成功
if (!$conn) {
    die("连接失败: " . mysqli_connect_error());
}

// 查询数据库
$sql = "SELECT * FROM users";
$result = mysqli_query($conn, $sql);

// 判断状态并执行操作
if (mysqli_num_rows($result) > 0) {
    // 输出数据
    while ($row = mysqli_fetch_assoc($result)) {
        echo "ID: " . $row["id"] . "，姓名: " . $row["name"] . "<br>";
    }
} else {
    echo "没有结果";
}

// 关闭连接
mysqli_close($conn);
?>