# File sample/psql.rb, line 137
def PSQLexec(ps, query)
  res = ps.db.exec(query)

  if res == nil
    printf(STDERR, "%s\n", ps.db.error())

  else
    if (res.status() == PGresult::COMMAND_OK ||
        res.status() == PGresult::TUPLES_OK)
      return res
    end

    if !ps.quiet
      printf(STDERR, "%s\n", ps.db.error())
    end

    res.clear()
  end

end