Update files images - php

Question

I have code where I upload 6 images in one part of my site, that code worked fine, now, I need to update or change any image that was uploaded, I mean I need to change the image number 3 and 6, for example, so I wrote this code
$i=0;
while ($i<=5){
if (!empty($_FILES['ufile']['name'][$i]) and ($_FILES['ufile']['name'][$i]<>"")){
$path[$i] = "../slider_new/".$_FILES['ufile']['name'][$i];
$path[$i] = str_replace(' ', '_',$path[$i]);
copy($_FILES['ufile']['tmp_name'][$i], $path[$i]);
echo "Ruta :".$path[$i]."<BR/>";
echo "File Name :".$_FILES['ufile']['name'][$i]."<BR/>";
echo "este es $i ",$i;
$sql="UPDATE accommo_main_images SET name='".$_FILES['ufile']['name'][$i]."',ruta='".$path[$i]."' where num='$num'";
$res=mysqli_query($cnx,$sql);
}
$i=$i+1;
}
The idea is that check the name and when it is different to "" so..... update the image, that is the idea but I don´t know why the code update all the 6 images with the image that I selected.
What cam be the problem ?
Thank you for you help

Answer 1

where num='$num'";
You use a SQL statement WHERE NUM=$num. Yet, you did not set $num anywhere in the code you gave us here. Most likely you never set the value of $num. You probally ment $i.
I'm guessing you also possibly made the same mistake in your upload code (initial upload) and therefor all images have number=0.
You are now updating images which have number 0, or empty string (depending on database field type) which would match every image you have in there.
Try running this code and check the table entries.
$res = mysqli_query($cnx,"SELECT num,name FROM accommo_main_images");
var_dump(mysqli_fetch_all($res,MYSQLI_ASSOC));