private static function get_supported_post_types_in() { global $wpdb; $post_types_in = ''; $post_types = self::get_supported_post_types(); $post_types_prepared = array(); foreach ($post_types as $post_type) { $post_types_prepared[] = $wpdb->prepare('%s', $post_type); } return implode(', ', $post_types_prepared); }