将图像上传到db在php中出错了

Question

1. 一切顺利，但得到了这个错误 Notice: Undefined index: image in C:\wamp\www\neos-final\update-image.php on line 21
2. 第21行是$image=$_FILES['image']['name'];

3. 如何处理这一行：（

   <form action="" method="post" enctype="multipart/form-data">
   <input type="file" name="image" id="image" size="40">
   <input name="" type="submit" value="upload" />
   
   </form>
   <?php 
   $con = mysql_connect('localhost', '', ''); //Update hostname
   mysql_select_db("test", $con); //Update database name
   
   define ("MAX_SIZE","1000"); 
   function getExtension($str)
   {
        $i = strrpos($str,".");
        if (!$i) { return ""; }
        $l = strlen($str) - $i;
        $ext = substr($str,$i+1,$l);
        return $ext;
   }
   
   $errors=0;
   $image=$_FILES['image']['name'];
   if ($image) 
   {
       $filename = stripslashes($_FILES['image']['name']);
       $extension = getExtension($filename);
       $extension = strtolower($extension);
       if ( ($extension != "jpg") && 
            ($extension != "jpeg") && 
            ($extension != "png") && 
            ($extension != "gif") && 
            ($extension != "JPG") && 
            ($extension != "JPEG") && 
            ($extension != "PNG") && 
            ($extension != "GIF") ) 
       {
           echo '<h3>Unknown extension!</h3>';
           $errors=1;
       }
       else
       {
           $size=filesize($_FILES['image']['tmp_name']);
   
           if ($size > MAX_SIZE*1024)
           {
               echo '<h4>You have exceeded the size limit!</h4>';
               $errors=1;
           }
   
           $image_name=time().'.'.$extension;
           $newname="images/".$image_name;
   
           $copied = copy($_FILES['image']['tmp_name'], $newname);
           if (!$copied) 
           {
               echo '<h3>Copy unsuccessfull!</h3>';
               $errors=1;
           }
           else echo '<h3>uploaded successfull!</h3>';
   
           mysql_query("insert into list (image) values('".$newname."')");
       }
   
       //Display image
       $rs=mysql_query("select * from list");
       if($rs)
           while($row=mysql_fetch_array($rs))
           {
            ?>
            <img width="150" src="<?php echo $row['image'];?>"><br>
            <?php 
           }
   }
   ?>
   

有什么想法吗？

Answer 1

当未定义任何数组变量索引时，会出现此通知Notice: Undefined index:。

在这里使用isset

if(isset($_FILES['image']))
{
    $image=$_FILES['image']['name'];
    //your rest of code here
}

Answer 2

Use php isset()

if(isset($_FILES['image']))
{
  // your code 
}