Images are not uploaded to specifically created folder in WordPress - php

Question

I tried to create a folder to store all my images but it will not upload on its specific upload folder inside my installed theme.
Here is my code:
if(isset($_FILES['file']['tmp_name']))
{
$num_files = count($_FILES['file']['tmp_name']);//count file upload
for($i=0; $i<$num_files; $i++)
{
if(!is_uploaded_file($_FILES['file']['tmp_name'][$i]))
{
echo "no file upload!!";
}else
{
if(#copy($_FILES['file']['tmp_name'][$i], "/upload/".$_FILES['file']['name'][$i]))
{
$path = "upload/".$_FILES['file']['name'][$i];
//$sql = "insert into tblImage value ('".$path."')";
}else
{
echo "cant upload";
}
}
}
}

Answer 1

It's difficult to figure out exactly what went wrong because I don't know your setup, but try these things:
It's inadvisable to use #copy in this case, especially while you're trying to figure out what's going wrong. Copy will return false on failures and show other error messages in exceptional situations, unless you prefix it with #. If your disk is full, for example, it'll fail silently. Just copy is likely more useful for this.
Your file naming is, at the very least, difficult to decipher. Specifically, what paths are you using? PHP file operations like copy require precise path information. Your path, /upload/, which is upload/ later, refers to something relative from some arbitrary place, that may change. To solve this, figure out a good absolute path. If you're uploading to WP uploads, start with wp_upload_dir and build from there.
Unless you absolutely need a copy of the file from the original location later, move it instead of copying it. Remember that you'd be moving it to the uploads folder, so it'd still be available later, just somewhere else. This also avails you to move_uploaded_file().
There are some great comments (like from #kabiir) about how to debug what you've got. It's hard to figure out exactly what's going wrong without some debugging information.
Try:
if(isset($_FILES['file']['tmp_name'])) {
for ($i = 0; $i < count($_FILES['file']['tmp_name']); $i++) {
$file = $_FILE['file']['tmp_name'][$i];
error_log('source: ' . $file);
if (is_uploaded_file($file) && isset($_FILE['file']['name'][$i])) {
$name = $_FILE['file']['name'][$i];
error_log('uploaded name: ' . $name);
$destination = trailingslashit(wp_upload_dir()) . $name;
error_log('destination: ' . $destination);
if (!move_uploaded_file($source, $destination)) {
echo 'failed to move file.';
continue;
}
// Now $destination contains where the file was moved to.
}
}
}
This code will output to your log (or wherever else you have error logging pointed to) the source file+path, the uploaded file name and destination file+path, per file.
Unless there's something very special you're doing, wp_handle_upload() should take care of all your needs without rewriting this. When it's done, it calls the wp_handle_upload filter. Hook to the end of that filter's chain to do your SQL or whatever else. There are also many plugins that do what you're trying to do and save you from having to code it yourself.
As a side note, you ought not create SQL entirely by hand in WP. Use the wpdb class, with the $wpdb->prepare() function. This also allows you to use $wpdb->prefix, which is the prefix for your table. (You've prefixed your table and created it according to WP standards, right?)