php - 非对象错误上的函数 rowCount()

Question

我在两个不同的页面上不断收到 function rowCount() on a non-object 错误。知道为什么会发生这种情况以及我如何更改代码以防止它发生吗？

错误-如下

Fatal error: Call to a member function rowCount() on a non-object in /opt/lampp/htdocs/xampp/index.php on line 35

代码:

$sql = "SELECT * from idea ORDER BY datetime DESC LIMIT 50;";
$result = $pdo->query($sql);

if($result->rowCount() > 0 && !empty($result)) // line 35
{
    foreach ($result as $row) 
    {
    $id = $row['id'];
    $title = $row['title'];
    $idea = $row['idea'];

    echo '<span class="idea" id="'.$id.'"><strong style="color: #0081C5">' . $title . "</strong>&nbsp;-&nbsp;" . $idea . '&nbsp;<a class="delete" href="#">[Delete]</a></span>';
    }
}

错误 - 如下所示

fatal error :在第 6 行的/opt/lampp/htdocs/xampp/assets/update.php 中的非对象上调用成员函数 rowCount()

代码

 $sql = "SELECT * from idea ORDER BY datetime DESC LIMIT 50;";
$result = $pdo->query($sql);

if($result->rowCount() > 0 && !empty($result)) // line 6
    {
        foreach ($result as $row) 
        {
        $id = $row['id'];
        $title = $row['title'];
        $idea = $row['idea'];

        echo '<span class="idea" id="'.$id.'"><strong style="color: #0081C5">' . $title . "</strong>&nbsp;-&nbsp;" . $idea . '&nbsp;<a class="delete" href="#">[Delete]</a></span>';
        }
    }

Answer 1

改成这样

if(!empty($result) AND $result->rowCount() > 0)