Loading Relational Data from Views in CodeIgniter - php

Question

I am using CodeIgniter
I have two tables -
Company
int id ,
varchar name
Employee int id, varchar name , int company_id
I have a simple controller called Employees Controller
<?php
class Employees extends CI_Controller {
public function index()
{
----
----
$data['employees'] = $selected_employees;
$this->load->view('employees/index',$data);
}
}
This controller passes an array of Employees to the view .
So inside my view , I can freely use employees[4].name , employees[3].id etc
Now If I want to show the name of the Company of the employees , it seems the only way is the Controller should pass another array with the name of the companies to the view . Is there any better way to achieve this - so that the controller doesnt have to explicitly have to send the data ?
For eg - say I want to access employees[4].company.name
I have been spoilt by Rails . I used to take these for granted .

Answer 1

The best way to go about this is using a join statement in your SQL query. The SQL query would typically look something like the following:
SELECT * FROM Employee JOIN Company ON Employee.company_id = Company.id
However, CodeIgniter's active record class will help us to simplify this (see http://ellislab.com/codeigniter/user-guide/database/active_record.html). In your model, you could write your query like so:
$this->db->select('*');
$this->db->from('Employee');
$this->db->join('Company', 'Employee.company_id = Company.id');
$query = $this->db->get();
You can tweak this to select the exact data that you want like you would any SQL query:
$this->db->select('Employee.id, Employee.name, Employee.company_id, Company.name AS company_name');
You can also add left, right, outer, inner, left outer, or right outer as a third parameter to the $this->db->join() function to allow for left joins, right joins, etc.
I would recommend using the Active Record class when possible in your CodeIgniter applications. It will help keep your queries clean, organized, and readable.

Answer 2

Do a join on your model
public function get_ selected_employees(){
$this->db->select('Employee.*, Company.name as company_name');
$this->db->from('Employee');
$this->db->join('Company', 'Employee.company_id = Company.id');
return $this->db->get()->result();
}
To get the company name just do employees[4].company_name