my %DataHash;
#get all values where the 'Data' colume = 'value'...?
my $sth = $dbh->prepare(" select ID, Data from table_name where Data=\"value\" ");
$sth->execute;
while ( my ( $ID, $Data) = $sth->fetchrow ) {
  $CountryDisplay{$ID} = "$Data";  # storing Data colum
} # end-while
$sth->finish