How can I move a custom taxonomy and its data from one post type to another?

Question

I'm writing a data conversion to merge one custom post type (Faculty) into another (Person).

Merging the actual CPT records is straightforward, but the two post types have similar custom taxonomies that I need to deal with:

• Faculty has a custom taxonomy, faculty-type, which has both terms and data
• Person has an empty custom taxonomy, person-type, which has neither terms nor data

I'd like to move the faculty-type taxonomy, including both terms and data, into the empty person-type taxonomy—so that when the Faculty-to-Person conversion finishes, all of the faculty-type data will be present as person-type data for the new Person records.

How can move the taxonomy data from Faculty to Person?

Answer 1

One simple query will accomplish this Assuming a wp_ table prefix:

UPDATE wp_term_taxonomy SET taxonomy = 'person-type' WHERE taxonomy = 'faculty-type';

Note that if the target taxonomy wasn't empty, additional work would be needed to avoid conflicting terms.