我正在尝试检索已存储到php-mysql中的数据。当我试图执行下面的代码时，出现了一个错误：
注意：试图在第27 0行的/storage/ssd5/459/2549459/public\u html/x.php中获取非对象的属性
x、 PHP

<?php 
    $conn = mysqli_connect("localhost" , "id2549459_salamnti" , "0000000000" , "id2549459_tutorial");
    if($conn -> connect_error){
        die("my connection faild" . $conn -> connect_error);
    }

    $sql = "SELECT id, military_num , firstname, lastname,image from students";
    $result = $conn-> query($sql);
    if($result -> num_rows > 0){
        while($row = $result-> fetch_assoc()){
            echo "<tr> <td>" . $row["id"] . "</td> <td>" . $row["militry_num"] . "</td> <td>". $row["firstname"]. "</td><td>" . $row["lastname"] . "</td><td>" . $row["image"] . "</td> </tr>";
        }
        echo "</table>";
    }
    else{
        echo "0 result";
    }
    $conn -> close();
?>