* @global wpdb $wpdb                  WordPress database abstraction object.
 */
function upgrade_230() {
	global $wp_current_db_version, $wpdb;

	if ( $wp_current_db_version < 5200 ) {
		populate_roles_230();
	}

	// Convert categories to terms.
	$tt_ids     = array();
	$have_tags  = false;
	$categories = $wpdb->get_results( "SELECT * FROM $wpdb->categories ORDER BY cat_ID" );
	foreach ( $categories as $category ) {
		$term_id     = (int) $category->cat_ID;
		$name        = $category->cat_name;
		$description = $category->category_description;
		$slug        = $category->category_nicename;
		$parent      = $category->category_parent;
		$term_group  = 0;

		// Associate terms with the same slug in a term group and make slugs unique.
		$exists = $wpdb->get_results( $wpdb->prepare( "SELECT term_id, term_group FROM $wpdb->terms WHERE slug = %s", $slug ) );
		if ( $exists ) {
			$term_group = $exists[0]->term_group;
			$id         = $exists[0]->term_id;
			$num        = 2;
			do {
				$alt_slug = $slug . "-$num";
				$num++;
				$slug_check = $wpdb->get_var( $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $alt_slug ) );
			} while ( $slug_check );

			$slug = $alt_slug;

			if ( empty( $term_group ) ) {
				$term_group = $wpdb->get_var( "SELECT MAX(term_group) FROM $wpdb->terms GROUP BY term_group" ) + 1;
				$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->terms SET term_group = %d WHERE term_id = %d", $term_group, $id ) );
			}
		}

		$wpdb->query(
			$wpdb->prepare(
				"INSERT INTO $wpdb->terms (term_id, name, slug, term_group) VALUES
		(%d, %s, %s, %d)",
				$term_id,
				$name,
				$slug,
				$term_group
			)
		);

		$count = 0;
		if ( ! empty( $category->category_count ) ) {
			$count    = (int) $category->category_count;
			$taxonomy = 'category';
			$wpdb->query( $wpdb->prepare( "INSERT INTO $wpdb->term_taxonomy (term_id, taxonomy, description, parent, count) VALUES ( %d, %s, %s, %d, %d)", $term_id, $taxonomy, $description, $parent, $count ) );
			$tt_ids[ $term_id ][ $taxonomy ] = (int) $wpdb->insert_id;
		}

		if ( ! empty( $category->link_count ) ) {
			$count    = (int) $category->link_count;
			$taxonomy = 'link_category';