Using Varibale for HAsh name

shawshankred has asked for the wisdom of the Perl Monks concerning the following question:

Perl experts.
I have a hash called tab2hash that has
tablenames as key and hashnames as value. I want to
initialize the hashes with the values from DB tables. And I
have the code below, however when i print the hashes
they are empty. This line is where the hash is being populated

$$VALUE_1{$k1} = $v1;

Please help with your suggestions.

my %tab2hash = qw(divisions divH regions regH);
sub initHashesArraysFromDB
{
    my ($k1, $v1);
    while ((my $KEY_1, my $VALUE_1) = each %tab2hash)
    {
        my $sth = $dbh->prepare("select * from $KEY_1");
        $sth->execute || die "Cannot execute query: " .DBI->errstr;
        while (my @row = $sth->fetchrow())
        {
            my $f1 = 0;
            foreach my $col (@row)
            {
                if($f1 == 0)
                {
                    $f1 = 1;
                    $k1 = $col;
                    $v1 = $col;
                }
                else
                {
                    $v1 .= "|" . $col;
                }
            }
            $$VALUE_1{$k1} = $v1;
        }
    }
}
[download]

Comment on Using Varibale for HAsh name Download Code

Replies are listed 'Best First'.
Re: Using Varibale for HAsh name by Corion (Patriarch) on Oct 22, 2010 at 16:36 UTC
Mark Jason Dominus says it better than I can: Why it's stupid to `use a variable as a variable name' (part 2 , part 3). Maybe if you debug your code by printing out the things at the various stages, you might find your error. Also consider using Data::Dumper. But I would avoid using a variable as a variable name in the first place.	[reply]
Re: Using Varibale for HAsh name by SuicideJunkie (Vicar) on Oct 22, 2010 at 16:38 UTC
As above, Don't. Try a HoH instead: `my %divisionsHash; my %regionsHash; my %hashes = (divisions=>\%divisionsHash, regions=>\%regionsHash); # Access it ala: $hashes{'regions'}{'North America'}; $hashes{'divisions'}{'Finance'};` [download]	[reply] [d/l]
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