script:
#!/usr/bin/perl
use DBI;
use HTML::Template;
use CGI;

my $q = CGI->new();

my $dbh = DBI->connect('DBI:Pg:dbname=testdb', '', '');
$dbh->{RaiseError} = 1;

$aref = $dbh->selectall_arrayref( q/select foo, bar from test_table where id = ?/, { Slice => {} }, $q->param('id') );

$dbh->disconnect;

my $template = HTML::Template->new(filename => 'test.tmpl', associate => $q, global_vars => 1);
$template->param(TEST_LOOP => $aref);
print $template->output();

template:
id = <TMPL_VAR NAME=ID>
<!--remove global_vars and only this first ID will print-->
<TMPL_LOOP NAME=TEST_LOOP>
  <p>
   id: <TMPL_VAR NAME=ID> <br \>
   foo:  <TMPL_VAR NAME=FOO> <br \>
   bar: <TMPL_VAR NAME=BAR>
  </p>
</TMPL_LOOP>