def bulk_insert_copyfrom(cursor, table_name, field_names, values):
    if not values: return

    #print "bulk copy from prepare..."

    str_vals = "n".join("t".join(adapt_to_str(val) for val in cur_vals) for cur_vals in values)
    strf = StringIO(str_vals)
    #print "bulk copy from execute..."
    cursor.copy_from(strf, table_name, columns=tuple(field_names))