For the life of me, I can't figure out what you meant to write. I presume that is because you formatted what you wrote nicely in your window, but did not include the tags that make paragraphs and separate code from text. So all of it became one long line.

You can try and re-edit your question using the tags to make your question more readable (See Writeup Formatting Tips). Trying to guess what you may have intended, I believe that perhaps there were two columns, something like:

order_id, time_mins
096000BN, 32 
096000BP, 85 
096000BG, 132 
096000Be, 85 
096000BP, 32
& etc.... ...
[download]

I guess that you mean: where there are matches in column 1, you want to see the time difference. Yes hashes would be the way to go here. In each hash position, keep an array of times. For example if we had this data in a file, we could read the file and do:

my %hash;
while (<>)
{ my ($id,$time) = split /,/;
  push @{$hash{$id}}, $time;
}
for (keys %hash)
{ print "@{$hash{$id}}\n";
}
[download]

As for your question: it's likely that using a hash of some sort will be useful, but it's not clear what you really need. In your sample, you have two instances of "096000BP" as the "order_id", with time_mins values of "85" and "32". Do you want an output like "096000BP, 53"? What if that order_id value occurs a third (fourth...) time -- what sort of differences should be reported then?

Depending on what you really want, a simple hash might do, or you might need a hash of arrays (for each order_id value, store the list of distinct time_mins values). Something like this will load such a structure, and check for cases where a given hash key occurred multiple times in the data:

my %orders;

while (<DATA>) {
    my ( $id, $mins ) = split /[\s,]+/;
    push @{$orders{$id}}, $mins  if ( $id );
}

for my $id ( keys %orders ) {
    if ( @{$orders{$id}} > 1 ) {
        my @times = @{$orders{$id}};
        # do something with @times
    }
}

__DATA__
096000BN, 32
096000BP, 85
096000BG, 132
096000Be, 85
096000BP, 32
[download]

(This'll cost me karma, but I can't resist)

Why don't you try editing you(r) post for grammar? :)

The next 2 top-level responses are much better examples of new user guidance - they point out that the post needs editing, as you did, but they also point out HOW to edit the post. PM markup isn't completely intuitive...


Mike