Problem with database queries - Printable Version

Problem with database queries - Printable Version

+- CodeIgniter Forums (https://forum.codeigniter.com)
+-- Forum: Archived Discussions (https://forum.codeigniter.com/forumdisplay.php?fid=20)
+--- Forum: Archived Development & Programming (https://forum.codeigniter.com/forumdisplay.php?fid=23)
+--- Thread: Problem with database queries (/showthread.php?tid=8887)

Problem with database queries - El Forum - 06-04-2008

[eluser]Olivier M.[/eluser]
Hi everybody...

I try to make a small application. I have written a small librairy :

Code:
&lt;?php if (!defined('BASEPATH')) exit('No direct script access allowed');

// MOTEUR DE CALCUL DE DIMECO2

class Dimeco2_lib

{

    var $CI;

    function calcul($data)

    {

        $CI =& get_instance();

        $dataprout=$data;

        $this->CI->db->select('jour, temperature');

        $query = $this->CI->db->get('biarritz2005_quotidien');

        $i=0;

        foreach ($query->result_array() as $row)

        {

            $data1[$i]=$row['jour'];

            $data2[$i]=$row['temperature'];

            $i++;

        }    

        $dataprout['donnees']=array("data1"=>$data1,"data2"=>$data2);

        return $dataprout;

    }

}

?&gt;

But it doesn't work and I don't know why because the same code works in a controller (without CI) :

Code:
&lt;?php

class Test extends Controller{

    function index(){

        $this->db->select('jour, temperature');

        $query = $this->db->get('biarritz2005_quotidien');

        $i=0;

        foreach ($query->result_array() as $row)

        {

            $data1[$i]=$row['jour'];

            $data2[$i]=$row['temperature'];

            $i++;

        }    

        print_r($data2);

    }

}

?&gt;

So my questions :
- someone can help me ???
- why we must use "$this->CI" in a library ?

Problem with database queries - El Forum - 06-04-2008

[eluser]crumpet[/eluser]
$CI =& get_instance();
neeeds to be
$this->CI =& get_instance();

Problem with database queries - El Forum - 06-05-2008

[eluser]Olivier M.[/eluser]
Thanks a lot !!!!

Why we must use this syntax ?

Problem with database queries - El Forum - 06-05-2008

[eluser]Michael Wales[/eluser]
Because you want to assign the class variable to the returned value of get_instance().

Your current code is assigned a method variable to that return value - PHP's scoping only allows this value to be accessible from within the same method (unless passed as a parameter).

The class variable is scoped to be accessible from the entire class.

PHP.net: Variable Scope

Problem with database queries - El Forum - 06-06-2008

[eluser]Olivier M.[/eluser]
Thank you Michael you're a good professor !