WordPress, MySQL, php - query results not acting as a string [duplicate] - php

Question

This question already has answers here:
How to modify an array's values by a foreach loop?
(2 answers)
Closed 8 years ago.
This is driving me nuts. I've searched for solutions but can't figure out what's wrong.
The situation... I have an SQL query running in WordPress, as follows:
SELECT distinct guid
FROM $wpdb->posts
WHERE post_status = 'inherit'
AND guid is not null
Dead simple. It returns a single column which contains a list of all the attachment media files currently stored on the system (well, not all of them, but it'll do as an explanation).
In a WP plugin function, I run the query:
$media_library_files = $wpdb->get_col($get_all_media,0);
That returns an array (I don't want an object) with values like:
[0] => http://mysitename.com/wp-content/uploads/2013/05/thumb_littlefile_blah.jpg
Then I want to process each one so that there's just the filename left. The problem is that, when I run a str_replace or pretty much any other string function on the contents, it doesn't work. For example:
$horrid_bit = 'http://mysitename.com/wp-content/uploads/2013/05/';
foreach($media_library_files as $item) {
$item = str_replace($horrid_bit,'',$item);
}
When I print_r the array after that, there's no visible change - every line is exactly the same as it was before.
I've tried using a (string) to cast $item, I've tried defining variables to do that, then working the str_replace on them, I've tried... loads of different things.
I have a feeling I'm missing something really simple, but I just can't see it. Is it because the column is varchar in the original table? Or something else?
Any help appreciated. Thanks!

Answer 1

PHP is not my 'native languague', but it seems like you're not modifying the values in the array. Did you try to put the modified string items (=minus the path) in a new array and use that one?
$horrid_bit = 'http://mysitename.com/wp-content/uploads/2013/05/';
$new_array = array();
foreach($media_library_files as $item) {
$new_item = str_replace($horrid_bit,'',$item);
$new_array.push($new_item);
}
//...use the items in the $new_array
Also, you might wanna just read the whole path string as an array (split on '/')and take the last element to get to the file.

Answer 2

$horrid_bit = 'http://mysitename.com/wp-content/uploads/2013/05/';
foreach($media_library_files as $key => $value) {
$media_library_files[$key] = str_replace($horrid_bit,'', $value);
}
But as Michael pointed out if you are not doing it this way for a specific purpose using basename would be better here, so you don't have to worry about the folder changing each month/year.
foreach($media_library_files as $key => $value) {
$media_library_files[$key] = basename($value);
}

Answer 3

You are not actually changing the value of $item in your array, you are instead creating a new variable, which is then overwritten every time your loop iterates.
It's also a good idea to check that the array is not empty before attempting a foreach() loop on it.
Finally, I've replaced str_replace() with basename() (as suggested in the comments under your question by #MichaelBerkowski).
if(!empty($media_library_files)) : foreach($media_library_files as $item) :
$media_library_files[$item] = basename($item);
endforeach;
endif;

Answer 4

str_replace() can handle arrays. No need for your foreach loop.
$horrid_bit = 'http://mysitename.com/wp-content/uploads/2013/05/';
$media_library_files = str_replace( $horrid_bit,'',$media_library_files );
On the other hand, since it seems you want to remove the path and get only the filename:
foreach($media_library_files as $key => $item) {
$media_library_files[$key] = basename($item);
}
This will change all entries to the filename only. The way you have it now you will have to change the $horrid_bit every month since the uploads are organized in year/month/ folders.