Common categories for two custom post types

When you use register_taxonomy(), the second argument is the object_type argument, which accepts either a string or an array. You can pass this an array of objects to apply the taxonomy to, and it will be common between those. So, for example: array( 'cpt_slug', 'post' ) would give you a common taxonomy between cpt_slug and post.

If you want to add the existing taxonomies to a new post type, you can use register_taxonomy_for_object_type()

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