A good rule of thumb is to always make the database do as much of the work as possible. For example, instead of reading data and then sorting it, add an 'ORDER BY' clause to your SELECT statement and read the already sorted data.

In this case, you don't really need a 'database' at all. Reading the columns of data from a text file would look something like this: 

use strict;

my %data;
my $headers = <DATA>;
while ( my $line = <DATA>) {
  chomp $line;
  my ($os,$release,$like) = split(/,/,$line);
  ++$data{$os}{$release}{ uc $like };
}

for my $os (sort keys %data) {
  for my $release (sort keys %{ $data{$os} } ) {
    my $yes = $data{$os}{$release}{'YES'} || '0';
    my $no = $data{$os}{$release}{'NO'} || '0';
    print "$os, $release, $yes, $no\n"; 
  }
}

__DATA__
OS,RELESASE,LIKE
Ubuntu,Warty,No
Ubuntu,Hoary,No
Ubuntu,Breezy,Yes
Ubuntu,Breazy,Yes
Fedora,Yarrow,Yes
Fedora,Stentz,No
Fedora,Yarrow,Yes
Fedora,Yarrow,Yes
Windows,XP PRO,Yes
Windows,XP PRO,Yes
Windows,XP Home,No
Windows,XP PRO,Yes

[download]

If you really want to use a database, then you could pull the data out like this: 

my $sth = $dbh->prepare("select OS, RELEASE, LIKE from $table");
$sth->execute();

while ( my ($os, $release, $like) = $sth->fetchrow ) {
  ++$data{$os}{$release}{$like};
}

[download]

In reply to Re: Count the Duplicate Entries and make them uniq by scorpio17
in thread Count the Duplicate Entries and make them uniq by slayedbylucifer

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