Delete all post meta except featured image

Question

My aim is to clear up my database entries. I did a migration from blogger which added many useless post_meta. I found a plugin (db reset) that has the option to reset/delete all post meta. However if I delete all post meta I lose my featured image (post thumbnails) settings.

I'm not very familiar with phpmyadmin. How can I delete all post meta except the featured image?

Answer 1

The below code will help you to remove all the post meta's except the thumbnail of a post.

    function kv_delete_all_meta_except_featuredimg(){
    $args = array( 'posts_per_page' => -1, 'post_status' => 'any',  'post_type' => array('attachment', 'page','post')); 
    $articles= get_posts( $args );

    foreach($articles as $article){
        if($article->post_type == 'attachment'){
            $myvals = get_post_meta($article->ID);
            foreach($myvals as $key=>$val)  {

                if($key == '_wp_attached_file' || $key == '_wp_attachment_metadata'){} else {
                    delete_post_meta($article->ID, $key);

                }
            }
        }else {
            $myvals = get_post_meta($article->ID);
            foreach($myvals as $key=>$val)  {
                if($key != '_thumbnail_id' ){
                    delete_post_meta($article->ID, $key);
                }
            }
        }
    }


}
add_action('init','kv_delete_all_meta_except_featuredimg');

Note :*** Remember This will remove all the post meta keys and its associated values. So take a backup before proceeding with it. Just add this function on your theme functions.php. Here i assumed you may have only these post types attachment, post, page. if you have any extra post types, add with it.

You can read here for more details I wrote an article about it. Kvcodes