use strict;
use DBI;
use DBD::CSV;
use Data::Dumper;

# Connect to CSV database
my $dbh = DBI->connect("DBI:CSV:csv_sep_char=\|")
                or die "Cannot connect: " . $DBI::errstr;
$dbh->{'csv_tables'}->{'addressbook'} = {'file'=>'addressbook.txt' };

# load address book entries
my $sth = $dbh->prepare("SELECT * FROM addressbook");
$sth->execute();

# store data in 2-tier hash table
my %data;
while (my $res = $sth->fetchrow_hashref()) # loop through data
{
   # create hash to store details
   my %rec = map { $_ => $res->{$_} } @{$sth->{NAME}};

   # create top level hash with last name as lookup key
   $data{$rec{"last"}} = \%rec;
}

# cleaning up
$sth->finish;
$dbh->disconnect;

# inspect our result
print Dumper(\%data);