use strict;
use Data::Dumper;
use DBI qw(:sql_types);
use Tie::IxHash;

tie my %results, "Tie::IxHash";

... connect to db ....

my $stmt = qq~SELECT * FROM registrants WHERE registrant_id = ?~;
%results = % { $dbh->selectrow_hashref($stmt, undef, $registrant_id) };

##</code><code>##

	my $stmt = qq~SELECT * FROM registrants, hotels, cadavers WHERE registrants.registrant_id = ? AND registrants.registrant_id = hotels.registrant_id~;
	%results = % { $dbh->selectrow_hashref($stmt, undef, $registrant_id) };