sub sql_write {
  my $hash = shift;
  my $dbh = DBI->connect("dbi:SQLite:dbname=mahou.db","","",
                          { RaiseError => 1, AutoCommit => 0 });
  eval {
    $dbh->do("DELETE FROM mahou_data");
    my $sth = $dbh->prepare("INSERT INTO mahou_data values(?,?,?,?,?)");
    foreach my $anime (sort keys %{$hash}) {
      $sth->execute( $anime, @{[ map { $hash->{$anime}{$_} } ('link','station','airtime','eta') ]} );
    }
    $dbh->commit; } 
  if $@ {
    $dbh->rollback;
    print "Failure.\n";
  }
  $dbh->disconnect;
}