Multi-Level Hashes

sunnyfedora99 has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying to access the 2nd dimension of a hash I created by getting values from a MySQL DB.

Creating the Hash:

 
sub read_database {
    #my ($dir) = @_;
    
    my $sth = $sql_query{sel_ftpuser}->execute() or die "can't execute
+ the query";
    
    print "CHECK_FTP: configuration seems to be OK\n";
    print "CHECK_FTP: reading information from DB...\n";
    
    my $sitedb;
    my $label;
    my $job_label;
    while (@site_row= $sql_query{sel_ftpuser}->fetchrow_array()) {
    ($label) = $site_row[2];
    ($job_label) = $site_row[0];
    if($label ne ""){
        $sitedb->{$label}->{$job_label}->{JOB_ID}  = $site_row[0];
        $sitedb->{$label}->{$job_label}->{SITE}  = $site_row[2];
        $sitedb->{$label}->{$job_label}->{HOST}  = $site_row[3];
        $sitedb->{$label}->{$job_label}->{MAIL} = $site_row[6];
        $sitedb->{$label}->{$job_label}->{LOCAL_DIRECTORY}  = $site_ro
+w[9];
        $sitedb->{$label}->{$job_label}->{REMOTE_DIRECTORY}  = $site_r
+ow[10];
        $sitedb->{$label}->{$job_label}->{PORT}  = $site_row[8];
    }
    }
    #print Dumper($sitedb);
    print "OK\n" if ($VERBOSE);
    return $sitedb;
}
[download]

This is what the hash looks like when I use Dumper:


$VAR1 = {
          'User1' => {
                       '7' => {
                                'HOST' => 'foobar.baz.com',
                                'REMOTE_DIRECTORY' => '/tmp/user1_test
+',
                                'JOB_ID' => '7',
                                'LOCAL_DIRECTORY' => 'to-user',
                                'MAIL' => 'baz@foobar.com',
                                'SITE' => 'user1',
                                'PORT' => '21'
                              },
                       '2' => {
                                'HOST' => 'foobar.baz.com',
                                'REMOTE_DIRECTORY' => '/tmp/user1_test
+',
                                'JOB_ID' => '7',
                                'LOCAL_DIRECTORY' => 'to-user',
                                'MAIL' => 'baz1@foobar.com',
                                'SITE' => 'user1',
                                'PORT' => '21'
                              }
                     },
          'User2' => {
                       '6' => {
                                'HOST' => 'foobar.baz.com',
                                'REMOTE_DIRECTORY' => '/tmp/user2_test
+',
                                'JOB_ID' => '7',
                                'LOCAL_DIRECTORY' => 'to-user',
                                'MAIL' => 'baz2@foobar.com',
                                'SITE' => 'user1',
                                'PORT' => '21'
                              }
                     }
        };
[download]

I then use a for loop to iterate through the hash

    foreach my $site_name (keys %$sitedb) {
    print "Checking $site_name ... \n";

    foreach my $subkey (keys %{$site_db{$site_name}}) {
        my @jobid = $site_db{$site_name}{$subkey};
        print Dumper(@jobid);
        print "Job ID: @jobid\n";
    }
    }
[download]

This doesn't seem to work for some reason. I can get the $site_name (first dimension) but it doesn't go any further. Am i missing something? Cheers!

Comment on Multi-Level Hashes Select or Download Code

Replies are listed 'Best First'.
Re: Multi-Level Hashes by toolic (Bishop) on Sep 20, 2011 at 12:36 UTC
Am i missing something? use strict and warnings This is probably closer to what you want: use warnings; use strict; use Data::Dumper; my $sitedb = { 'User1' => { '7' => { 'HOST' => 'foobar.baz.com', 'REMOTE_DIRECTORY' => '/tmp/user1_test', 'JOB_ID' => '7', 'LOCAL_DIRECTORY' => 'to-user', 'MAIL' => 'baz@foobar.com', 'SITE' => 'user1', 'PORT' => '21' }, '2' => { 'HOST' => 'foobar.baz.com', 'REMOTE_DIRECTORY' => '/tmp/user1_test', 'JOB_ID' => '7', 'LOCAL_DIRECTORY' => 'to-user', 'MAIL' => 'baz1@foobar.com', 'SITE' => 'user1', 'PORT' => '21' } }, 'User2' => { '6' => { 'HOST' => 'foobar.baz.com', 'REMOTE_DIRECTORY' => '/tmp/user2_test', 'JOB_ID' => '7', 'LOCAL_DIRECTORY' => 'to-user', 'MAIL' => 'baz2@foobar.com', 'SITE' => 'user1', 'PORT' => '21' } } }; foreach my $site_name ( keys %{ $sitedb } ) { print "Checking $site_name ... \n"; foreach my $subkey ( keys %{ $sitedb->{$site_name} } ) { my @jobid = $sitedb->{$site_name}{$subkey}; print Dumper(@jobid); print "Job ID: @jobid\n"; } } __END__ Checking User1 ... $VAR1 = { 'HOST' => 'foobar.baz.com', 'JOB_ID' => '7', 'LOCAL_DIRECTORY' => 'to-user', 'MAIL' => 'baz@foobar.com', 'PORT' => '21', 'REMOTE_DIRECTORY' => '/tmp/user1_test', 'SITE' => 'user1' }; Job ID: HASH(0x60b220) $VAR1 = { 'HOST' => 'foobar.baz.com', 'JOB_ID' => '7', 'LOCAL_DIRECTORY' => 'to-user', 'MAIL' => 'baz1@foobar.com', 'PORT' => '21', 'REMOTE_DIRECTORY' => '/tmp/user1_test', 'SITE' => 'user1' }; Job ID: HASH(0x661ff0) Checking User2 ... $VAR1 = { 'HOST' => 'foobar.baz.com', 'JOB_ID' => '7', 'LOCAL_DIRECTORY' => 'to-user', 'MAIL' => 'baz2@foobar.com', 'PORT' => '21', 'REMOTE_DIRECTORY' => '/tmp/user2_test', 'SITE' => 'user1' }; Job ID: HASH(0x624400) [download] perlreftut perldsc	[reply] [d/l]
Re^2: Multi-Level Hashes by AnomalousMonk (Archbishop) on Sep 20, 2011 at 13:13 UTC
sunnyfedora99: Also note that the statement `my @jobid = $sitedb->{$site_name}{$subkey};` will never put anything other than a single element, a hash reference, into the `@jobid` array, hence the content printed by the `print "Job ID: @jobid\n";` statement.	[reply] [d/l] [select]
Re^2: Multi-Level Hashes by sunnyfedora99 (Novice) on Sep 20, 2011 at 12:45 UTC
Ahhh sweet... That sorted it. Cheers toolic.	[reply]
Re: Multi-Level Hashes by jwkrahn (Abbot) on Sep 20, 2011 at 12:28 UTC
`foreach my $site_name (keys %$sitedb) { print "Checking $site_name ... \n"; foreach my $subkey (keys %{$site_db{$site_name}}) { my @jobid = $site_db{$site_name}{$subkey}; print Dumper(@jobid); print "Job ID: @jobid\n"; } }` [download] You are using `%$sitedb` in the outer loop and `$site_db` in the inner loop. Also, you are not dereferencing the hash keys in the inner loop.	[reply] [d/l] [select]