package TDmodule;use DBI;sub new{  $self={};  $self->{select_db}=undef;  $self->{delete_db}=undef;  $self->{insert_db}=undef;  $self->{update_db}=undef;  bless $self;  return $self;}sub connect_db{  my $self=shift;  if(@_){    $self->{
   'connect_db'}=DBI->connect("DBI:mysql:database=@_[0];host=@_[1]","@_[2]","@_[3]") or die "No:$!\n";  }  return $self->{
   'connect_db'};}sub select_db{  my $self=shift;  if(@_){      my $select=@_[0]->prepare(@_[1]);      $select->execute();      $self{select_db}=$select;  }  return $self{select_db};  @_[0]->disconnect;}sub update_db{  my $self=shift;  if(@_){      eval{        $self->{update_db}=@_[0]->do(@_[1]);      } or die "No\n";  }}sub insert_db{  my $self=shift;  if(@_){      eval{        $self->{insert_db}=@_[0]->do(@_[1]);      } or die "No\n";  }}sub delete_db{  my $self=shift;  if(@_){      eval{        $self->{delete_db}=@_[0]->do(@_[1]);      } or die "No\n";  }}1;