package Tie::DBI;

use 5.008003;
use strict;
use warnings;

use base 'Tie::Scalar';

use DBI;

our $VERSION = '0.01';

sub TIESCALAR {
  my $class = shift;
  my ($dsn, $user, $pass) = @_;
  my $self = {
    dbh => undef,
  };
  $self->{dbh} = DBI->connect($dsn, $user, $pass);
  bless $self, $class;
}

sub STORE {
  my ($self, $value) = @_;
  if ( $self->{sth} && ref($value) eq 'ARRAY' ) {
    $self->{sth}->execute(@$value);
  } else {
    $self->{sth} = $self->{dbh}->prepare($value);
    if ( $self->{sth}->FETCH('NUM_OF_PARAMS') == 0 ) {
      $self->{sth}->execute();
    }
  }
}

sub FETCH {
  my ($self) = @_;
  return undef if !$self->{sth} || $self->{dbh}->err;
  return $self->{sth}->fetchrow_arrayref() || 0;
}

1;

##</code><code>##

my $dbh;
tie $dbh, 'Tie::DBI', $dsn, $user, $pass;
$dbh = "select * from table where field = $value";
while ( my $row = $dbh ) {
  print $row->[0], "\n";
}

##</code><code>##

$dbh = "select * from table where field = ?";
$dbh = [$value];
while ( my $row = $dbh ) {
  print $row->[0], "\n";
}