Look at DBI Recipes, and you'll find several ways of dealing with hashes.

Among them there is something like:

my $sth=$dbh->prepare($query);
$sth->execute or die $DBI::errstr;
my $array_of_hashes = $sth->fetchall_arrayref({});
for my $href (@$array_of_hashes) {
    # do something smart with $href
}
[download]

HTH