my @wall_data = ();
while(my $wallref = $wallpostquery->fetchrow_hashref()) {
    my %walldata;
       
    $walldata{WALL_SUBJECT} = $wallref->{'SUBJECT'};
    $walldata{WALL_DATE} = $wallref->{'DATE'};
    $walldata{WALL_POSTID} = $wallref->{'POSTID'};
    $walldata{WALL_MESSAGE} = $wallref->{'MESSAGE'};
       
    push (@wall_data, \%walldata); ## i have also tried push @wall_data, {%walldata};
}   
$template->param(WALL_LOOP => \@wall_data);