...
my $main_tmpl = HTML::Template->new(filename => 'search.tmpl', die_on_bad_params => 1);
...

sub data {
    
 my $id = shift || return;
 
 my $sql = qq{SELECT distinct name, city, state
              FROM   my_table
              WHERE  name  like ? order by name asc};

 my $sth = $dbh->prepare($sql);
    $sth->execute(${id}.'%') or die "SQL Error: $DBI::errstr\n";

 my $all_data = $sth->fetchall_arrayref({});

 my @loop_data = (); # initialize an array to hold loop
 
 # Count things
 my $c = 0; my @count;
 
 foreach my $row (@{$all_data}) {
   $c++;

   my %row_data;      # get a fresh hash for the row data

   # fill in these rows
   $row_data{NAME}     = $row->{NAME}  || '';
   $row_data{CITY}   = $row->{CITY}  || '';
   $row_data{STATE}  = $row->{STATE} || '';

   push @count, $c;
   # the crucial step - push a reference to this row into the loop
   push(@loop_data, \%row_data);
 }
 
 # Count things
 my $counter = @count;

# I need to load the data here but it doesn't.
 # load values into the template
 $main_tmpl->param(
                    ALL_DATA => \@loop_data,
                    COUNT => $counter,
                  );
 
 # If sending data through json use this
 # This works if I use jQuery to process the returned json from here
 # but I am trying to load the data using  HTML::Template
=code
 print $q->header(-type => "application/json");
 if(@loop_data){
   print to_json(\@loop_data);
   exit;
 }else{
   my $json_string = [{ result => "No data"}];
   print to_json($json_string);
   exit;
 }
=cut
             
} # end sub