# Warning, untested code, to be used for inspiration only

my %user_info;

my $query = "update tUser Set ".
	(join ", " map {"$_ = ?"} sort keys %user_info).
	" where UserID = $user_info{UserID}";
my $sth = $dbh->prepare($query) or die;
$sth->execute(map {$user_info{$_}} sort keys %user_info);