my $rows = $dbh->selectall_arrayref($SQL,{Columns =>{}}) ;
$template->param(ROWS => $rows || []);

##</code><code>##

<!-- TMPL_LOOP NAME=ROWS -->
<tr>
.
.
.
<td>
<input type="text" value = "<!-- TMPL_VAR NAME=Detail -->" size="43" name="Detail">
</td>
<td>
<input type="submit" value="Update">
</td>
 </tr>
<!-- /TMPL_LOOP -->

##</code><code>##

$ticket = $query->param('TicketNo');
$detail = $query->param('Detail');
.
.
.

my $temp1 = "UPDATE TSIssuesTable ";
my $temp2 = "SET Detail = ?";
my $temp3 = "WHERE ";
my $temp4 = "TicketNo = $ticket";
	
$SQL = $temp1.$temp2.$temp3.$temp4;
$sth1 = $dbh->prepare( $SQL );
$sth1->execute($details);
...