use DBI;
use Data::Dumper;

my $dbh = DBI->connect("DBI:CSV:f_dir=C:/;csv_sep_char=\t")
       or die $DBI::errstr;
$dbh->{'csv_tables'}->{'info'} = { 'file' => 'info.csv'};
my $sth = $dbh->prepare("SELECT PartID FROM info"); 
$sth->execute(); 

my %hash;
while(my $test = $sth->fetchrow_hashref){ 
     unless($hash{$test->{PartID}}){
       $hash{$test->{PartID}} = 1;
     }
     else{
       print "Schon vorhanden: ",$test->{PartID},"\n";
     }
}

print Dumper(\%hash);