How can I UN-attach media from a post?

Question

I'm having a trouble un-attaching media from a post without deleting it entirely from my site. Is there a simple way to unattach an image from a post for instance?

Answer 1

I learned from Brian Fegter that you can Un-attach an image from a post while participating in this question: Can I attach an image to a different post?

It isn't exactly "simple", but not to difficult. It's the only solution I've been able to find.

Answer 2

Is this what you're looking for?

e.g. Remove all image attachments from a post

//get all image attachments
$attachments = get_children( 
                    array(
                        'post_parent'       => $post->ID,
                        'post_mime_type'    => 'image',
                        'post_type'         => 'attachment'
                    ) 
                );

//loop through the array
if( !empty( $attachments ) ){   
    foreach( $attachments as $attachment ){
        // Update the post into the database
          wp_update_post( array(
                    'ID' => $attachment->ID,
                    'post_parent' => 0
                )
            );
    }
}

However, please take note of the caution when using wp_update_post.

Alternate method using $wpdb

//replace this with the above inside the foreach block;
global $wpdb;
$wpdb->query(
    "
    UPDATE $wpdb->posts 
    SET post_parent = 0
    WHERE ID = $attachment->id
        AND post_type = 'attachment'
    "
);

Answer 3

As of WordPress 4.2 this functionality is built in. Click the Detach link in media list view.

For older versions, there's a plugin which does the same thing: https://wordpress.org/plugins/unattach/

Unattach is a very simple plugin which allows detaching images and other media from WordPress posts, pages and other content types.