Problem with this code?

I'm trying to parse a file to a database. this is the type of information in the file:
DISCID=a50b390c
DTITLE=Various Artists / Put your Tongue to the Rail (Disc 1)
DYEAR=1999
DGENRE=Data
TTITLE0=Nothing Is True - Mae Pang
TTITLE1=It's too Late - Psyclone Rangers
TTITLE2=Three Sisters - Thorazine
TTITLE3=People Who Died - Bootleg Thorazine Nightmare
TTITLE4=Catholic Boy - Bottom
TTITLE5=City Drops into the Night - Stomaboy w/ Marrow
TTITLE6=I Want the Angel - Jen Hess
TTITLE7=Day and Night - Iota
TTITLE8=Differing Touch - Marah
TTITLE9=Crow - Del Pess
TTITLE10=Plain Division - Mia Johnson
TTITLE11=Wicked Gravity - Sesitive Pricks

I have 4 tables as follow which I think are fully normalised:
CREATE TABLE ARTIST (
id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(90) NOT NULL
);

CREATE TABLE SONG (
id  INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(90) NOT NULL,
tracknumber INT UNSIGNED NOT NULL,
artist_id INT UNSIGNED NOT NULL
);

CREATE TABLE ALBUM  (
id  INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(90) NOT NULL,
year INT UNSIGNED NOT NULL,
genre VARCHAR(90) NOT NULL,
disc_id VARCHAR(90) NOT NULL,
UNIQUE KEY (disc_id)
);

CREATE TABLE ALBUM_SONG (
song_id INT UNSIGNED NOT NULL,
album_id INT UNSIGNED NOT NULL,
UNIQUE KEY (song_id, album_id)
);

My problem is the code below. there is something wrong with the $album_id variable below, can anyone see why? Also, how can I populate the ALBUM_SONG table?
#!usr/bin/perl
use DBI;
use strict;
use warnings;
use diagnostics;
use FileHandle;

my $db_handle = DBI->connect("dbi:mysql:database=kilkennp_db2;host=mysql.cs.tcd.ie;user=kilkennp;password=yee5iePh")
    or die "Couldn't connect to database: $DBI::errstr\n";

my $fh = new FileHandle;
$fh->open("<$ARGV[0]") or die "could not open file\n";

open(OUTTRACKS,">makefree") or die "could not open trackbigrams\n";

my($album_id,$artist_id,$title,$year,$genre,$disc_id);
while (<$fh>)
      {
            if(/DTITLE=(.*)/)
            {
            my $length = length ($_);
            if ($length > 8)
                  {
                  if( /DTITLE=(.*) \/ (.*)/ )
                        {
                        my $artist = $1;
                        $title = $2;
                        $db_handle->do('INSERT INTO ARTIST (name) VALUES (?);',undef,$artist);
                        $artist_id=($db_handle->selectrow_array("SELECT id FROM ARTIST WHERE name=?;",undef,$artist))[0];
                        }
                  else
                        {
                        $title = "$1";
                        my $artist = "N/A";
                        $db_handle->do('INSERT INTO ARTIST (name) VALUES (?);',undef,$artist);
                        $artist_id=($db_handle->selectrow_array("SELECT id FROM ARTIST WHERE name=?;",undef,$artist))[0];
                        }

                  }
            elsif ($length == 8)
                  {
                  $title = "N/A";
                  my $artist = "N/A";
                  $db_handle->do('INSERT INTO ARTIST (name) VALUES (?);',undef,$artist);
                  $artist_id=($db_handle->selectrow_array("SELECT id FROM ARTIST WHERE name=?;",undef,$artist))[0];

                  }
            }
            elsif( /DYEAR=(.*)/ )
                  {
                  my $length = length ($_);
                  if ($length > 7)
                        {
                        $year = $1;
                        }
                  elsif ($length == 7)
                        {
                        $year = 1;
                        }
            }
            elsif( m/DGENRE=(.*)/ )
                  {
                  my $length = length ($_);
                  if ($length > 8)
                        {
                        $genre = $1;
                        }
                  elsif ($length == 8)
                        {
                        $genre = "N/A";
                        }
                  }
            elsif( m/DISCID=(.*)/ )
                  {
                  my $length = length ($_);
                  if ($length > 8)
                        {
                        $disc_id = $1;
                        }
                  elsif ($length == 8)
                        {
                        $genre = "N/A";
                        }
                  }
            elsif( /TTITLE(\d*)=(.*)/ )
                  {
                  my $value = length($2);
                  if ($value > 0)
                        {
                   $db_handle->do("INSERT INTO SONG (name,tracknumber,artist_id,album_id) VALUES (?,?,?,?);",undef,$2,$1,$artist_id,$album_id);
                        }
                  else
                        {
                        my $trackname = $2;
                        $trackname = "N/A";
                         $db_handle->do("INSERT INTO SONG (name,tracknumber,artist_id,album_id) VALUES (?,?,?,?);",undef,$trackname,$1,$artist_id,$album_id);
                        }
                  }
            
      if( $title && $year && $genre && $disc_id )
            {
            $db_handle->do("INSERT INTO ALBUM (name,year,genre,disc_id) VALUES (?,?,?,?);",undef,$title,$year,$genre,$disc_id);
            $album_id=($db_handle->selectrow_array("SELECT id FROM ALBUM WHERE name=? AND year=? AND genre=? AND disc_id=?;",undef,$title,$year,$genre,$disc_id))[0];
            undef $_ for($title,$year,$genre,$disc_id);
            }
      }

$fh->close();
$db_handle->disconnect();
close(OUTTRACKS);