Inpsyde\MultilingualPress\API\WPDBContentRelations::relate_all_terms PHP Method

    public function relate_all_terms($source_site_id, $destination_site_id)
    {
        $inserted = 0;
        $query = "\nINSERT INTO {$this->table} (\n\tml_source_blogid,\n\tml_source_elementid,\n\tml_blogid,\n\tml_elementid,\n\tml_type\n)\nSELECT %d, term_taxonomy_id, %d, term_taxonomy_id, 'term'\nFROM {$this->db->term_taxonomy}";
        foreach ([$source_site_id, $destination_site_id] as $site_id) {
            $inserted += (int) $this->db->query($this->db->prepare($query, $source_site_id, $site_id));
        }
        return $inserted;
    }