Remove a WordPress Taxonomy using MySQL query and WPDB

remove-taxonomy-from-wp-using-wpdb.php

global $wpdb;

$taxonomy_name = 'taxonomy_name_goes_here';

$wpdb->query( 
  "DELETE FROM {$wpdb->terms} AS t 
   WHERE t.term_id IN (
    SELECT tt.term_id FROM {$wpdb->term_taxonomy} AS tt
    WHERE tt.taxonomy = '{$taxonomy_name}'
   )"
);

$wpdb->query( 
  "DELETE FROM {$wpdb->term_relationships} AS tr 
   WHERE tr.term_taxonomy_id IN (
    SELECT tt.term_taxonomy_id FROM {$wpdb->term_taxonomy} AS tt
    WHERE tt.taxonomy = '{$taxonomy_name}'
   )"
);

$wpdb->query( 
  "DELETE FROM {$wpdb->term_taxonomy} 
   WHERE taxonomy = '{$taxonomy_name}'"
);