Question

我正在尝试显示数据库中的列表但是在运行该代码时它说“您的数据中没有列出产品”，但实际上有我的数据列表......

<?php 
$con = new mysqli("localhost", "root", "3250", "shopone");


// Check connection
if (mysqli_connect_errno($con))
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

// This block grabs the whole list of product for viewing
$product_list = "";
$sql = "SELECT * FROM product ORDER BY product_id DESC";

$result=mysqli_query($con,$sql);

    while($row = mysqli_fetch_array($result)){ 
             $product_id = $row["product_id"];
             $product_name = $row["product_name"];
             $product_category = $row["product_category"];
              $product_retail_price = $row["product_retail_price"];
              $product_price = $row["product_price"];
              $product_detail = $row["product_detail"];
              $product_image = $row["screenshot"];
              $product_thumbnail = $row["product_thumbnail"];
              $product_discount = $row["product_discount"];
            $screenshot = $row["screenshot"];

             $product_list .= '<table width="80%" border="1">
  <tr>
    <td width="172" valign="top"> echo <img src="' . GW_UPLOADPATH . $screenshot .'" width="111" height="149" alt="<?php echo $product_name; ?>" /><br />
      <a href="../product_images/<?php echo $product_id; ?>.jpg">View Full Size Image</a></td>
    <td width="85" class="product-text">' . $product_id . '</td>
    <td width="402" class="product-text">' . $product_name . '</td>
    <td width="108" align="center" class="product-text">' . $product_price . '</td>
    <td width="34" align="center" class="product-text"><a rel="leanModal" href="edit_product.php?pid=' . $product_id . '">Edit</a></td>

    <td width="56" align="center" class="product-text"><a rel="leanModal" href="product.php?deleteid=' . $product_id . '">Delete</a></td>
        <td width="56" align="center" class="product-text"><a href="view_product.php?pid=' . $product_id . '">View</a></td>
  </tr>
</table> ';              

    }

    $product_list = "You have no product listed in your data yet";

?>

然后我得到的结果是没有显示“你的数据中没有产品清单”，我该怎么解决呢！

Answer 1

将最后一项作业更改为：

if (empty($product_list)) {
    $product_list = "You have no product listed in your data yet";
}

您正在使用该错误消息替换从数据库中检索到的所有结果。

<?php echo ... ?>作业中$product_list所做的所有地点都应该是连接 - 您只能在内联HTML中使用它，而不能在字符串中使用。

您可能不希望为数据库中的每一行启动新的<table>。通常只有一个HTML表，每个数据库行对应一个HTML行。

Answer 2

也许是特权问题。但首先评论最后一行并试一试。

Answer 3

您在最后一个语句中覆盖$ product_list，这就是您获得上次给变量赋值的原因。此外，作为提示，在while循环中，您可以保存每条记录的行，因为您已在数组中使用它。最后，您可以在之前打开表格，然后在之后关闭它。

<?php 
$con = new mysqli("localhost", "root", "3250", "shopone");
// Check connection
if (mysqli_connect_errno($con))
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// This block grabs the whole list of product for viewing
$sql = "SELECT * FROM product ORDER BY product_id DESC";
$result = mysqli_query($con,$sql);

//you can add this check to add 'empty table' message if no result
if(mysql_num_rows()>0)
{    
    $product_list = '<table>';         
    while($row = mysqli_fetch_array($result))
    { 
       $product_list.= '<tr>'.
                       '<td>'.$row["product_id"].'</td>'.
                       // ....
                       // do the same with all rows
                       // ....
                       '<td>'.$row["screenshot"].'</td>'.
                       '</tr>';         
    }
    $product_list.= '</table>';
}
else
{
    $product_list = "You have no product listed in your data yet";
} 
//print
echo $product_list;
?>

不从数据库显示

3 个答案: