In order to use this library, we will need CI version 1.7.2, so if you have been following this book with a previous version, download version 1.7.2 and unzip it. We have unzipped it in a folder called codeigniterc. If you do the same, you will be able to check your CI installation in http://localhost/codeigniterc/. Once this is done, we will create a new database; call it cart or whatever you want. For our example we will call it cart.

We need to configure our CI installation to be able to use this database. Remember that the database configuration file was placed in application/config/database.php:

$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root";
$db['default']['password'] = "root";
$db['default']['database'] = "cart";
$db['default']['dbdriver'] = "mysql";
$db['default']['dbprefix'] = "";
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = "";
$db['default']['char_set'] = "utf8";
$db['default']['dbcollat'] = "utf8_general_ci";

Again, the most important values are:

The easiest way to see if this configuration is working, is to autoload the database library. Remember this was done in the application/config/autoload.php file; we can see the libraries, just add database in the array name as shown:

$autoload['libraries'] = array('database');

After this is done, when we refresh http://localhost/codeigniterc/, we can check if the configuration is working. If something goes wrong we will see a message like:

A Database Error Occurred

We are almost done with the preparations. Now we need to create a new table in our database using the following code:

CREATE TABLE IF NOT EXISTS `ci_sessions` (
session_id varchar(40) DEFAULT '0' NOT NULL,
ip_address varchar(16) DEFAULT '0' NOT NULL,
user_agent varchar(50) NOT NULL,
last_activity int(10) unsigned DEFAULT 0 NOT NULL,
user_data text NOT NULL,
PRIMARY KEY (session_id)
);

The cart library also uses the Session class. To save cart data into the database, we need to create the mentioned table. Once this is done, we can start using the cart library.