in reply to Unique Array from DB

Hashes are great for grouping. 

my %users_by_account;

...

push @{ $users_by_account{$account_name} }, $username;

...

for my $account_name (sort keys %users_by_account) {
   my $users = $users_by_account{$account_name};

   print("Account $account_name\n");

   for my $username (@$users) {
      print("$username\n");
   }

   print("\n");
}

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Re^2: Unique Array from DB
by Corion (Patriarch) on Mar 09, 2009 at 16:13 UTC

    Why use a hash and sort yourself when the DB can do that already?

    select ...
order by account_name, username

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    then, in Perl:

    my $last_account;
while (my $row = $sth->fetchrow_arrayref({ Slice => {})) {
    if (! defined $last_account or $last_account ne $row->{account_nam
+e}) {
        if (defined $last_account) {
            print "\n";
        };
        $last_account = $row->{account_name};
        print "Account $last_account\n",
    };
    print $row->{username};
};

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Re^2: Unique Array from DB
by Anonymous Monk on Mar 09, 2009 at 17:08 UTC
    If one more field from the DB would have to be added to this like including the date the account was opened,
    $date_opened = $pointer->{'dateopened'};
    Is that the case of one of those multidimensional hash?
    Printing,
    Group A - Name=Mary - Date Opened 03/03/2009
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