如果没有选择新图像，则保留现有图像

Question

在事件表单中，如果没有上传新图像，我会尝试保留（更新）现有图像。表格的其余部分保留位置、时间等信息。 但是，当您在点击更新后尝试使用现有图像（在您点击更新之前确实显示）时，现有图像会消失并且不会将其自身包含在更新中。我是业余爱好者。 ..您的帮助表示赞赏。下面是一些代码：

   function eventadd(){

    if($_REQUEST['startampm'] == 'PM') $_REQUEST['starthour'] += 12;
    $datetimescheduled =        $_REQUEST['startyear'].'-'.$_REQUEST['startmonth'].
                        '-'.$_REQUEST['startdate'].' '.$_REQUEST['starthour'] .
                        ':'.$_REQUEST['startminute'].':00';

    $filetmp = $_FILES['file_img']['tmp_name'];
    $filename = $_FILES['file_img']['name'];
    $filetype = $_FILES['file_img']['type'];
    $filepath = "flyers/".$filename;


    move_uploaded_file($filetmp,$filepath);

          $query = 'insert into eventcalendar '.
            '(dateentered,datetimescheduled,title,location,description,img_name,img_path,img_type,soldout,private,free,paydoor,ticketlink,ticketURL) '.
            'values '.'(now(),"'.$datetimescheduled.'","'.stripslashes($_REQUEST['title']).'","'.addslashes($_REQUEST['location']).'","'.stripslashes($_REQUEST['description']).'","'.$filename.'","'.$filepath.'","'.$filetype.'","'.addslashes($_REQUEST['soldout']).'","'.addslashes($_REQUEST['private']).'","'.addslashes($_REQUEST['free']).'","'.addslashes($_REQUEST['paydoor']).'","'.addslashes($_REQUEST['ticketlink']).'","'.addslashes($_REQUEST['ticketURL']).'")';


            $result = mysql_query($query) or die("Query failed : " . mysql_error());

这里是更新表格，图片没有保留的地方：

// update existing event action
if($updateevent) {

if($startampm == 'PM') $starthour += 12;
$datetimescheduled = $startyear.'-'.$startmonth.'-'.$startdate.' '.$starthour .':'.$startminute.':00';

// added to try to fix update image
$filetmp = $_FILES['file_img']['tmp_name'];
$filename = $_FILES['file_img']['name'];
$filetype = $_FILES['file_img']['type'];
$filepath = "flyers/".$filename;
// end fix - also see image name field didnt work

move_uploaded_file($filetmp,$filepath);

$query = 'update eventcalendar set '.
        'datetimescheduled = "'.$datetimescheduled.'",'.
        'title = "'.stripslashes($title).'",'.
        'location = "'.addslashes($location).'",'.
        'description = "'.stripslashes($description).'",'.
        'img_name = "'.$filename.'",'.
        'img_path = "'.$filepath.'",'.
        'img_type = "'.$filetype.'",'.
        'soldout = "'.stripslashes($soldout).'",'.
        'private = "'.stripslashes($private).'",'.
        'free = "'.stripslashes($free).'",'.
        'paydoor = "'.stripslashes($paydoor).'",'.
        'ticketlink = "'.stripslashes($ticketlink).'",'.
        'ticketURL = "'.stripslashes($ticketURL).'"'.
        'where id = '.$id;



$result = mysql_query($query) or die("Query failed : " . mysql_error());

HTML 表单摘录：

<td align="right">IMAGE:</td>
            <td><input name="file_img" type="file"><?php echo $row['img_path'] ?><?php echo '<img src='. $row['img_path'] .' class="img-responsive no-img thumb-img">'; ?><br>

同样，当提交这个没有新图像的 HTML 表单时，现有图像不会自行更新。

我得到的只是：传单/（没有图像名称） 虽然它显示为：<img src='. $row['img_path'] .

但在点击SUBMIT后不包含自身。

Answer 1

首先，mysql_query 已经过时，因此，您应该使用 mysqli_query。不建议在查询中传递变量，因为它鼓励 sql 注入 - 建议您使用准备好的语句。

要回答您的问题，您可以在更新前检查是否上传了图片。如果尚未上传图像或从数据库中选择现有图像，解决方案将是忽略图像列。这是一个示例，如果尚未使用准备好的语句上传图像（代码尚未测试），则从数据库中选择现有图像：

$filetmp = $_FILES['file_img']['tmp_name'];
$filename = $_FILES['file_img']['name'];
$filetype = $_FILES['file_img']['type'];
$filepath = "flyers/".$filename;
// end fix - also see image name field didnt work

move_uploaded_file($filetmp,$filepath);

 // if a file has not been uploaded get the flyer from the DB
  if(empty($filename))
    {
      // CHANGE $connection variable to whatever your db connection is called
      $select_image = mysqli_prepare($connection, "SELECT img_name, img_path, img_type FROM eventcalendar WHERE id = ? ");
       mysqli_stmt_bind_param($select_image, 'i', $id);
       mysqli_stmt_execute($select_image);
       mysqli_stmt_bind_result($select_image, $filename, $filepath, $filetype);
       mysqli_stmt_fetch($select_image);
       mysqli_stmt_close($select_image);
     }

  // CHANGE $connection variable to whatever your db connection is called
   $query = mysqli_prepare($connection, "UPDATE eventcalendar SET datetimescheduled = ?, title = ?, location = ?, 
description = ?, img_name = ?, img_path = ?, img_type = ?, soldout = ?, private = ?, 
free = ?, paydoor = ?, ticketlink = ?, ticketURL = ? WHERE id = ? ");

   mysqli_stmt_bind_param($query, 'sssssssssssssi', $datetimescheduled, stripslashes($title), addslashes($location), 
stripslashes($description), $filename, $filepath, $filetype, stripslashes($soldout), stripslashes($private), 
stripslashes($free), stripslashes($paydoor), stripslashes($ticketlink), stripslashes($ticketURL), $id);

    mysqli_stmt_execute($query);
    mysqli_stmt_close($query);