无法在php函数中运行db查询

Question

I have created a function in my views and have tried to make a query within the php function but i do not know I am getting and unexpected error which was never been seen in my entire career can anyone help me out to get rid from this error?

Severity: Error --> Using $this when not in object context /application/views/includes/create_calendar.php 51

This is my controller

class Booking extends CI_Controller {
    public function __construct() {
        parent::__construct();
        $this->load->helper(array("form", "url"));
        $this->load->library('session');
        $this->load->database();
    }

    public function get_calendar() {
        $this->load->view('includes/create_calendar');
    }
}

This is the file in which I am trying to run a query views/includes/create_calendar.php

function getCalender($year = '',$month = '') {  
   $sql       = $this->db->get('calendar');
   if($day == $sql->row()->day_off) { $per_off = $sql->row()->per_off; }

                        echo "<p>".$day." Off</p>";
}

Answer 1

In CodeIgniter usage, if you need to use one of the classes that is available in the "super object", you must first get an instance of the super object:

$CI =& get_instance();
$CI->db->get('calendar');

This DB class may not even be loaded. If that's the case, then before you use db:

$CI->load->database();

To clarify, as soon as you go in that function, you've removed $this from the variable scope, like this simple test:

class Test {

    public $foo = 'bar';

    public function index() {
        function baz(){
            return $this->foo;
        }
        echo baz();
    }
}

$t = new Test;
$t->index();

You could do something like the following, but that's really messy:

class Test {

    public $foo = 'bar';

    public function index() {
        function baz($x) {
            return $x->foo;
        }
        echo baz($this);
    }
}

$t = new Test;
$t->index();

The best thing for you to do is find another cleaner way to do what you are doing. You wouldn't normally want calls to your database and functions in your views. It goes against what MVC is all about.