Use MySQL to store data from Amazon’s API via Perl scripts

I really like Amazon.com and I have been a Prime member for several years. Along with millions of different items for sale, Amazon has an affiliate program, where you can earn money advertising products on your web site. When a visitor to your site clicks on a link and orders a product from Amazon, you earn a small commission on the total sale. As an affiliate, you have access to Amazon’s Product Advertising API for obtaining product information. But, you can use this information for many other purposes.

The Amazon API is like most other API’s, and their API web site provides you with code examples and explains how it all works. I am going to show you how a Perl program which you can use to access the API data and store it in a MySQL database. This program was modified from one of the examples on the Amazon API web site.

I wrote a book in 2014, and I wanted to be able to track the book’s ranking on Amazon. I have a couple of friends who wrote books as well, so I tracked their ranking at the same time. By using the API, I can get a lot of information about any product – including my book’s ranking. And, I can keep a historical record of the ranks in a MySQL database. You could also use this to track the price of a product, and you could have the script notify you if the price changed or went below a certain threshold. Example – if you want to know when the price of that 55″ 4K television drops below $599 – you can use the API to check the price once an hour – and send you an alert when the price drops. Most prices and ranks only change (at the most) once an hour, so running the script every five minutes isn’t necessary.

To access Amazon’s API, you will need to register as an Amazon affiliate, and obtain your own Access Keys (Access Key ID and Secret Access Key). In the Perl script, this information goes here:

use constant myAWSId	    => 'Access Key ID';
use constant myAWSSecret    => 'Secret Access Key';
use constant myEndPoint	    => 'ecs.amazonaws.com';

The following Perl script is an example of getting the rank for a particular item. To use the script and to access Amazon’s API, you have to supply the product’s ASIN (Amazon Standard Identification Number), or for a book, you can supply the ISBN (International Standard Book Number). The ASIN is usually found in the URL for a product – as in http://www.amazon.com/gp/product/B00R0ZM5W4 – where B00R0ZM5W4 is the ASIN. I use a MySQL table to store the ranking information (you can modify the table to also include other information). Here is the CREATE TABLE statement for this table:

CREATE TABLE `ranks` (
  `idranks` int(11) NOT NULL AUTO_INCREMENT,
  `product_id` varchar(15) DEFAULT NULL,
  `product_title` varchar(100) DEFAULT NULL,
  `product_rank` varchar(15) DEFAULT NULL,
  `rank_datetime` datetime DEFAULT NULL,
  PRIMARY KEY (`idranks`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=latin1

The script also has a sub-routine (named sub ConnectToMySql) which uses connection information stored in a text file one directory below the directory where the script is executed. In this example, the file name is accessAMAZON, and the file contains this connection information (in this order):

database_name
IP_address
mysql_user_name
mysql_password

You can hardcode the connection information directly into the script if you prefer.

The script will also output all of the potential variables and values for each ASIN/ISBN, and this information is stored in a text file with the name equal to the ASIN/ISBN, and with a prefix of “.txt”. Example: B00R0ZM5W4.txt There are over a hundred different variables

The script is named amazonrank.pl and may be found on github at: https://github.com/ScriptingMySQL/PerlFiles.

Here is the script: (remember to add your own Amazon access key information into the script)

#!/usr/bin/perl -w

##############################################################################################
# Copyright 2009,2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file 
# except in compliance with the License. A copy of the License is located at
#
#	   http://aws.amazon.com/apache2.0/
#
# or in the "LICENSE.txt" file accompanying this file. This file is distributed on an "AS IS"
# BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under the License. 
#
#############################################################################################
#
#  Amazon Product Advertising API
#  Signed Requests Sample Code
#
#  API Version: 2009-03-31/2013-08-01
#
#############################################################################################

#use strict;
#use warnings;

#no warnings 'uninitialized';

use Data::Dumper;
use DBD::mysql;
use DBI;

use RequestSignatureHelper;
use LWP::UserAgent;
use XML::Simple;

use constant myAWSId		=> 'Access Key ID';
use constant myAWSSecret	=> 'Secret Access Key';
use constant myEndPoint		=> 'ecs.amazonaws.com';

my $Database = "amazonrank";

# see if user provided ItemId on command-line
# my $itemId = shift @ARGV || '0545010225';

# ----------------------------------------------------------------------------------
# this has to be near the top - as other parts of the script rely on these figures
# ----------------------------------------------------------------------------------

my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime time;

$year = $year + 1900;
$mon = $mon + 1;

# add a zero if the value is less than 10

if ($sec < 10) { $sec = "0$sec"; }
if ($min < 10) { $min = "0$min"; }
if ($hour < 10) { $hour = "0$hour"; }
if ($mday < 10) { $mday = "0$mday"; }
if ($mon < 10) { $mon = "0$mon"; }
if ($year < 10) { $year = "0$year"; }
if ($wday < 10) { $wday = "0$wday"; }
if ($yday < 10) { $yday = "0$yday"; }
if ($isdst $fileout") or die print "Couldn't open log_file: $!";

print "Retrieving rank for $itemId - ";

# Set up the helper
my $helper = new RequestSignatureHelper (
	+RequestSignatureHelper::kAWSAccessKeyId => myAWSId,
	+RequestSignatureHelper::kAWSSecretKey => myAWSSecret,
	+RequestSignatureHelper::kEndPoint => myEndPoint,
);

# A simple ItemLookup request
my $request = {
	Service => 'AWSECommerceService',
	Operation => 'ItemLookup',
	Version => '2013-08-01',
	ItemId => $itemId,
	AssociateTag => 'scmy-20',
	ResponseGroup => 'Large',
};

# Sign the request
my $signedRequest = $helper->sign($request);

# We can use the helper's canonicalize() function to construct the query string too.
my $queryString = $helper->canonicalize($signedRequest);
my $url = "http://" . myEndPoint . "/onca/xml?" . $queryString;
#print "Sending request to URL: $url \n";

my $ua = new LWP::UserAgent();
my $response = $ua->get($url);
my $content = $response->content();
#print "Recieved Response: $content \n";

my $xmlParser = new XML::Simple();
my $xml = $xmlParser->XMLin($content);

# This prints out all of the item information into a text file
print OUT "Parsed XML is: " . Dumper($xml) . "\n";

if ($response->is_success()) {

	# Here is where you extract the information for each item
	my $title = $xml->{Items}->{Item}->{ItemAttributes}->{Title};
	my $rank = $xml->{Items}->{Item}->{SalesRank};
	my $price = $xml->{Items}->{Item}->{Offers}->{Offer}->{OfferListing}->{Price}->{FormattedPrice};

	# option to print to screen - uncomment this next line
	#	print "Item $itemId is titled \"$title\" and ranked $rank\n";

if (length($rank) > 1)

{
	$dbh = ConnectToMySql($Database);	
	$query = "insert into ranks (product_id, product_rank, rank_datetime, product_title) values ('$itemId', '$rank', '$DateTime','$title')";
	$sth = $dbh->prepare($query);
	$sth->execute();
	$dbh->disconnect;

	print "$rank || $title || $itemId || \$$price\n\n";
}

else

{
	print "Rank for: $title is unavailable.\n\n";
}

# optional sleep 
# sleep 5;


} else {
	my $error = findError($xml);
	if (defined $error) {
	print "Error: " . $error->{Code} . ": " . $error->{Message} . "\n";
	} else {
	print "Unknown Error!\n";
	}
}

sub findError {
	my $xml = shift;
	
	return undef unless ref($xml) eq 'HASH';

	if (exists $xml->{Error}) { return $xml->{Error}; };

	for (keys %$xml) {
	my $error = findError($xml->{$_});
	return $error if defined $error;
	}

	return undef;
}


# end - foreach
}

#----------------------------------------------------------------------
sub ConnectToMySql {
#----------------------------------------------------------------------

  # my ($db) = @_;

   open(PW, "<..\/accessAMAZON") || die "Can't access login credentials";
   my $db= ;
   my $host= ;
   my $userid= ;
   my $passwd= ;

   chomp($db);
   chomp($host);
   chomp($userid);
   chomp($passwd);
   
   my $connectionInfo="dbi:mysql:$db;$host:3306";
   close(PW);

   # make connection to database
   my $l_dbh = DBI->connect($connectionInfo,$userid,$passwd);
   return $l_dbh;

}

I am not the best Perl programmer, nor am I an expert at the Amazon API, so there may be a better/easier way to do this. Good luck with the scripts and let me know how they work for you. And follow me on Twitter at ScriptingMySQL and TonyDarnell.

 


Tony Darnell is a Principal Sales Consultant for MySQL, a division of Oracle, Inc. MySQL is the world’s most popular open-source database program. Tony may be reached at info [at] ScriptingMySQL.com and on LinkedIn.
Tony is the author of Twenty Forty-Four: The League of Patriots

 

Visit http://2044thebook.com for more information.

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