Taxonomy to Post Type. Every Taxonomy Item can be Producer or Developer

If you are open to use plugin, you can use PostType (avoid taxonomies) for both entities using this: https://wordpress.org/plugins/posts-to-posts/

Documented here: https://github.com/scribu/wp-posts-to-posts/wiki

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)