Re: How to retain a value passed from another link to a script

[SuicideJunkie]

You need to show your code if you want help with it.

First thoughts:

1. Show the function that can't see the value
2. Show the function that can see the value
3. Show the differences between the two functions; where they are located, how they are called.

[terrykhatri]

Hi, Here is the script, the ELSE routine of Action EDIT gets execute, when I click on EDIT button this Action does not get excuted the form shows up empty with $ordered as null, I can't get to Action UPDATE because it comes after Action EDIT.

#!/usr/local/bin/perl
use strict;
use CGI;
use CGI::Carp 'fatalsToBrowser'; #remove for prod
use DBI;

# get form parameters
my $q = new CGI;
my $action = $q->param('go');
my $orderid = $q->param('orderid');
my $msg = "";
my $dbh = dbh(); # connect to db

$dbh->do("SET search_path to northwind") or die;

my $sql = 'SELECT  
             a."OrderID", b."ProductName", a."UnitPrice", a."Quantity"
+, a."Discount"  
           FROM  
             "Order_Details" a, "Products" b  
           WHERE 
             a."ProductID" = b."ProductID" AND "OrderID" = ? ';

my $hr = $dbh->selectrow_hashref($sql,undef,$orderid);

#change validation to suit
if ( ($action eq "UPDATE") && ($orderid =~ /\d+/)) {
  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";
} else {
  $msg = "Please complete form";
}

# build html page
my $style = q!
  body { background-color: pink ; color: #3300cc; }
  .container { width: 500px; clear: both; }
  .container input { width: 100%; clear: both;}
!;

# Send out the header and form
print $q->header;
print $q->start_html(-title=>'Order details',
                     -style=>{ -code=>$style } );

if ( ($action eq "EDIT") && ($orderid =~ /\d+/)) {
 print qq!<h1 style="color:3300CC">Update Order Details for order # ? 
+</h1>!;
 print qq!<div class="container">
<form action="" method="post">
<input type="hidden" name="ordid" value="$hr->{'OrderID'}"/>
Product Name :<input name="productname" value="$hr->{'ProductName'}" r
+eadonly/><br/>
Unit Price :<input name="unitprice" value="$hr->{'UnitPrice'}" /><br/>
Quantity :<input name="quantity" value="$hr->{'Quantity'}" /><br/>
Discount :<input name="discount" value="$hr->{'Discount'}" /><br/>
<input type="submit" name="go" value="UPDATE"/>
</form></div><hr/>!;
$msg = "";
} else {
print qq!<h1 style="color:3300CC">Order Details for order # $orderid</
+h1>!;
print qq!<div class="container">

<form action="" method="post">
<input type="hidden" name="ordid" value="$hr->{'OrderID'}"/>
Product Name :<input name="productname" value="$hr->{'ProductName'}" r
+eadonly/><br/>
Unit Price :<input name="unitprice" value="$hr->{'UnitPrice'}" readonl
+y/><br/>
Quantity :<input name="quantity" value="$hr->{'Quantity'}" readonly/><
+br/>
Discount :<input name="discount" value="$hr->{'Discount'}" readonly/><
+br/>
<input type="submit" name="go" value="EDIT"/>
</form></div><hr/>!;

$msg = "Record details fetched - $sql, $orderid";
}
 
  # Standard links to the rest of the application
  print <<"FOOTER";
<b>$msg</b>
<hr/>
Jump to - <a href="viewemp.pl">View Employees Listing</a><br/>
Jump to - <a href="addemp.pl">Add an Employee</a><br/>
Jump to - <a href="editemp.pl">Edit an Employee details</a><br/>
Jump to - <a href="updatephoto.pl">Add or update Employee Photo</a><br
+/>
<hr/>
Edited by Terry on July, 06 2014.
FOOTER
print $q->end_html;

# 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;
}

[poj]

Spot the parameter name difference

my $orderid = $q->param('orderid');

<input type="hidden" name="ordid" value="$hr->{'OrderID'}"/>

When you fix that this will fail (not enough bind variables)

my $sql = qq! UPDATE
                   "Order_Details"
                SET
                   "UnitPrice" = ?,
                   "Quantity"  = ?,
                   "Discount"  = ?
                WHERE "OrderID" = ? !;
               
  my $count = $dbh->do( $sql,undef,$orderid );

poj

[terrykhatri]

Many thanks Poj, You are the only ONE :) OK you are right the update is failing I changed the code though :

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";

Please help !!!

[terrykhatri]

Many many many thank Poj, you are amazing !!! I have one more queston to ask and that is pagination, I need to paginate a form which has too many records, I have been searching google but I DONT quite understand how to implement it, if you can help me that will be great !!! Rgds. Terry

[terrykhatri]

Hi Marto, I have tried to implement it by googling through various examples but no example is working or fitting to my situation, I am learning by getting the code, the help provided to me by your monks specially Poj has helped me do so many other webpages which you don't know, once I am done with this project I am going study all the links given to me in this forum I promise OK !! Thanks for putting up with me !!

[terrykhatri]

Here is the script that needs pagination :

#!/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;
}

If you need the template code used in this script I will post it. Many thank !!!