Question

我有mysql_num_rows（）函数的问题。我检查了查询（它有正确的语法，我在sql中获得结果）和连接到数据库，一切似乎都可以工作。

// some code here, connecting to database and working query to db
$query = "SELECT ff_client.email FROM ff_order, ff_client WHERE ff_order.id = '$order_number' AND ff_order.client_id = ff_client.id AND ff_client.email = '$email'";
if (!$result = mysqli_query($db, $query))   {
    echo '<p>Query wasn\'t found.</p>';
    exit;
}
if (!$num = mysql_num_rows($result)) {   // < the problem
    echo 'error';
}
if ($num == 0) {
    echo '<p>Insert proper email address.</p>';
}
else
{
    $_SESSION['crazyfotoApp']['token'] = $order_number;
    $_SESSION['crazyfotoApp']['multiformat'] = 1;
    header('Location: http://www.my.page.pl/zamow-odbitki.php?u=1');
}

我得到了这个结果：

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /mnt/sda3/www/www1.my.page.pl/recover.php on line 37
error
Insert proper email address.

Answer 1

尝试mysqli_num_rows而不是mysql_num_rows

Answer 2

那是因为$ result只在第一个if语句中知道。您需要将其分解并使其“全局”可访问。

此外，如果$ result失败，您将收到该错误，因此您需要将子if-ifs嵌套在if(!$row =....

中

Answer 3

mysql_error（）;说？什么是var_dump（）;当你检查$ result时说的var_dump（$结果）;

mysql_num_rows错误

3 个答案: