sub my_quote {
  my $s = shift;
  if (defined($s)) {
    my $us = decode("gbk", $s);
    $us =~ s/'/''/g;
    $us =~ s/\\/\\\\/g;

    my $gs = encode("gbk", $us);
    $gs = "'" . $gs . "'";

    return $gs;
  } else {
    return "NULL";
  }
}