if ( ($action eq "UPDATE") && ($orderid =~ /\d+/)) {
my @data=();
  my @fields = qw!unitprice quantity discount !; 
  for my $f (@fields){
    push @data,$q->param($f) || '' ;
  }
  push @data,$orderid;

  my $sql = qq! UPDATE
                   "Order_Details"
                SET
                   "UnitPrice" = ?,
                   "Quantity"  = ?,
                   "Discount"  = ?
                WHERE "OrderID" = ? !;

  my $count = $dbh->do( $sql,undef,$orderid );
  $msg = "$count Record updated - $sql, $orderid";
[download]

my $count = $dbh->do( $sql,undef,@data );  # not $orderid
[download]

poj

this node may be of use perl pagination links
poj

once I am done with this project I am going study all the links given to me in this forum I promise OK !!

Wrong approach. Try to use these links to solve yourself your current problems, and ask for help when, despite having used these links and tried to code solutions, you get into a dead end. Asking other people to solve the problems for you will not make you improving, which does by no way mean that you should not be asking for help (sometimes we all need help from others, nobody was born with the Full and True Knowledge), it will only possibly solve your immediate problem. But really trying hard to solve yourself your problems will really get you a long way forward, even if you occasionally have to ask for some help when stumbling on some road blocks.

You're never gonna get anywhere if you hope to get away from hard work by asking others to do it for you. Please understand me well, I am not chastising you, nor trying to teach you a lesson, I am only trying to help you going forward and becoming a good problem solver, and I believe many monks here, including myself, make their living from having become good at problem solving (whether it is in the Perl language, some other language or some other technology), and the only way to get good at problem solving is to work hard solving problems. It may look very challenging at first, but it is in fine very rewarding.

#!/usr/local/bin/perl

use DBI;
use CGI;
use strict;
use HTML::Template;

my $CGI = CGI->new();

my $dbh = dbh(); # connect to db
$dbh->do("SET search_path to northwind") or die;

# grab the stuff from the database
my $sql = qq!SELECT
                 a."OrderID", b."CompanyName" AS "CustomerName", 
                 c."FirstName"::text || ' ' ||c."LastName"::text AS "E
+mployeeName",
                 a."OrderDate", a."RequiredDate", a."ShippedDate", d."
+CompanyName" AS "ShipVia",
                 a."Freight", a."ShipName", a."ShipAddress", a."ShipCi
+ty", a."ShipRegion",
                 a."ShipPostalCode", a."ShipCountry" 
             FROM
                 "Orders" a, "Customers" b, "Employees" c, "Shippers" 
+d
             WHERE
                 a."CustomerID" = b."CustomerID" AND
                 a."EmployeeID" = c."EmployeeID" AND
                 a."ShipVia"    = d."ShipperID"
             ORDER BY 1 !;
my $sth = $dbh->prepare($sql);
$sth->execute();

# prepare a data structure for HTML::Template
my $rows;
push @{$rows}, $_ while $_ = $sth->fetchrow_hashref();

# instantiate the template and substitute the values
my $template = HTML::Template->new(filename => 'Orders.tmpl');
$template->param(ROWS => $rows);

print $CGI->header();

print $template->output();


$dbh->disconnect();

# connect to database
sub dbh {
  my $dsn = 'DBI:Pg:dbname=northwind;host=localhost';
  my $user = 'postgres';
  my $pwd  = 'postgres';
  my $dbh = DBI -> connect($dsn,$user,$pwd,{'RaiseError' => 1});
  return $dbh;
}
[download]

This isn't a code writing service. It looks as thought you've just outsourced your task to several forums