WordPress删除文章同时自动删除缩略图及图片附件

WordPress删除文章时，文章内所上传到媒体库的图片等附件不会自动删除，占用了网站空间，因此下面说明通过几行代码的简单方式实现在删除文章时自动删除缩略图以及图片附件，这样就不用手动去媒体库寻找并删除，准确而且效率高。

/* 删除文章时删除图片附件 */
function delete_post_and_attachments($post_ID) {
    global $wpdb;
    //删除特色图片
    $thumbnails = $wpdb->get_results( "SELECT * FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND post_id = $post_ID" );
        foreach ( $thumbnails as $thumbnail ) {
        wp_delete_attachment( $thumbnail->meta_value, true );
    }
    //删除图片附件
    $attachments = $wpdb->get_results( "SELECT * FROM $wpdb->posts WHERE post_parent = $post_ID AND post_type = 'attachment'" );
        foreach ( $attachments as $attachment ) {
        wp_delete_attachment( $attachment->ID, true );
    }
    $wpdb->query( "DELETE FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND post_id = $post_ID" );
}
add_action('before_delete_post', 'delete_post_and_attachments');