As a starting point I will describe you how to setup a 'Hello World' application.
First create a sample database and setup the following table.
After you've completed that what you have do do next is setting up the model. Models are just PHP classes that contain functions which work with information from the database. Then make a helloworld_model.php file in the "system/application/models" folder. In this file, create a Helloworld_model class. In that class create a Helloworld_model construct and a function called getData. Make sure you name the file with same name of your class.
After that you need to create the controller in order to load the data from the model class and pass it to view class for displaying. In the folder "system/application/controllers", create a file called helloworld.php. In this new file, we'll create a class which has the same name as the file. Within this class, you need to create a function called "index". This is the default function that will be called when loading the page if no other method is called. In order to pass data we retrieve from the model to a view we need to assign it to an array item and pass the array as a variable to the view file.
The final part is to display the data to the end user. You need to setup the view file for that. You can pass an array of variables to the view through the second argument of the load model function. To make the view, create a new file called helloworld_view.php in the "system/application/view" folder. We just need to create a normal html file to display the information from the database. To display all the records received, we put it in a "foreach" loop.
When you type the [url_of_your_site]/index.php/helloworld, you should see the output now. So that's all from our 'Hello World' application. Cheers!
