open (OUTPUT, ">>./output.txt") or die "Cannot open the output file: $!";

foreach my $id (@ids) {

    my $sth = $dbh->prepare("select long_string from my_table where id=?");
    $sth->execute($id);
    my $long_string = $sth->fetchrow_array();
    $sth->finish();
    undef($sth);

    my %count;
    my @letters = split("", $long_string);
    
    foreach my $letter (@letters) {
        $count{$letter}++;
        
    }
    
    undef(@letters);
    undef($long_string);
    
    # Print out the counts for each string
    
    print OUTPUT "$id\t" .
        ($count{A} || 0) . "\t" .
        ($count{B} || 0) . "\t" .
        ($count{C} || 0) . "\t" .
        ($count{D} || 0) . "\t" .
        ($count{E} || 0) . "\t" .
        ($count{F} || 0) . "\t" .
        ($count{G} || 0) . "\t" .
        ($count{H} || 0) . "\t" .
        ($count{I} || 0) . "\t" .
        ($count{J} || 0) . "\t" .
        ($count{K} || 0) . "\t" .
        ($count{L} || 0) . "\t" .
        ($count{M} || 0) . "\t" .
        ($count{N} || 0) . "\t" .
        ($count{O} || 0) . "\t" .
        ($count{P} || 0) . "\t" .
        ($count{Q} || 0) . "\t" .
        ($count{R} || 0) . "\t" .
        ($count{S} || 0) . "\t" .
        ($count{T} || 0) . "\t" .
        ($count{U} || 0) . "\t" .
        ($count{V} || 0) . "\t" .
        ($count{W} || 0) . "\t" .
        ($count{X} || 0) . "\t" .
        ($count{Y} || 0) . "\t" .
        ($count{Z} || 0) . "\n";
        
    undef(%count);
    
}

close (OUTPUT) or die "Cannot close the output file: $!";