Selecting one value from database?

fancms

Posted: 22 October 2007 09:06 AM

[ Ignore ]

Grad Student

Total Posts: 35

Joined 10-20-2007

I need to select one value from one row in the database. With the database class I used previously before finding CI I could accomplish this by doing

$variable = $db->get_var("SELECT somevalue FROM sometable WHERE something='therowvalue'"); 

This would allow me to use $variable as-is throughout my code.

I’ve been trying to figure out how to do this (select one value from a table) in CI. Right now I have

$this->db->select('value'); #Because I need the value
$this->db->where('variable', 'siteoverview'); #Because I need the variable column entitled siteoverview
$grab_cache = $this->db->get("settings"); #From the settings table 

This produces

CI_DB_mysql_result Object
(
    [conn_id] => Resource id #27
    [result_id] => Resource id #31
    [result_array] => Array
        (
        )

    [result_object] => Array
        (
        )

    [current_row] => 0
    [num_rows] => 1
) 

I’m a bit lost here. I haven’t been able to find my answer in the docs, the forums, or the wiki. I know this is a basic question (and I’ll likely feel pretty dumb when I find/get the answer) but I’m hoping someone will be kind enough to clarify a bit.

Thanks!

Signature

PHP + CodeIgniter

Profile

ELRafael

Posted: 22 October 2007 09:18 AM

[ Ignore ] [ # 1 ]

Lab Assistant

Total Posts: 298

Joined 09-11-2007

$tabela = 'usuarios';
$this->db->select('nome');  //Will find 'Rafael', my name
$this->b->where('cidade', 'São Bernardo do Campo'); //Where user in my city
$query = $this->get($tabela); // Get this f&#xck; name!

$nome = $this->db->row();
$nome = $nome->nome;

echo $nome //Produces Rafael 

Capisce fancms?

It’s a ugly example, but i hope you understand

Signature

Rafael
Last.fm
Twitter

“Because they’re stupid, that’s why. That’s why everybody does everything!”

Profile

xwero

Posted: 22 October 2007 09:25 AM

[ Ignore ] [ # 2 ]

Sr. Research Associate

Total Posts: 4839

Joined 07-14-2006

fancms - 22 October 2007 09:06 AM

$this->db->select('value'); #Because I need the value $this->db->where('variable', 'siteoverview'); #Because I need the variable column entitled siteoverview $grab_cache = $this->db->get("settings"); #From the settings table

You are on the right path but you have to go more specific

$this->db->select('value'); #Because I need the value
$this->db->where('variable', 'siteoverview'); #Because I need the variable column entitled siteoverview
$query = $this->db->get("settings"); #From the settings table
$row = $query->row; // get the row
echo $row->value 

If you want to put it in a function

function scalar($table,$field,$where)
   $this->db->select($field); #Because I need the value
   $this->db->where($where); #Because I need the variable column    entitled siteoverview
   $query = $this->db->get($table); #From the settings table
   $row = $query->row_array(); // get the row
   return $row[$field]; // return the value
} 

Profile

fancms

Posted: 22 October 2007 09:46 AM

[ Ignore ] [ # 3 ]

Grad Student

Total Posts: 35

Joined 10-20-2007

Thank you both, Rafael and xwero; it makes a lot more sense now

One more question - since this is a function I’d definitely want to reuse, is it something I could make into a plugin / helper? How would I go about running the database queries from an external function file like that? When I tried saving it as a plugin, loading it in the controller file, and running the function, I got the message:

Fatal error: Using $this when not in object context

Signature

PHP + CodeIgniter

Profile

Armchair Samurai

Posted: 22 October 2007 10:15 AM

[ Ignore ] [ # 4 ]

Lab Assistant

Total Posts: 237

Joined 10-02-2007

If you’re going to use CI resources (like the DB class) in your custom libraries, helpers and plug-ins, you need to use the get_instance() function.

Check the Creating Libraries section in the User Guide.

Signature

ウェブデザイン・イラストレーション・グラフィックデザイン
“If I have to be smarter to use your technology, then your technology sucks.”

Profile

xwero

Posted: 22 October 2007 10:27 AM

[ Ignore ] [ # 5 ]

Sr. Research Associate

Total Posts: 4839

Joined 07-14-2006

If you want to use it as a function you can extend the model library, name the file MY_Model and put it in the application/libraries directory and add following code

class MY_Model extends Model {

    function My_Model()
    {
        parent::Model();
    }

    function scalar($table,$field,$where)
    {
       $this->db->select($field);
       $this->db->where($where);
       $query = $this->db->get($table);
       $row = $query->row_array();
       return $row[$field];
    } 
} 

This way you don’t have to load it yourself and you can use $this->scalar() to call the function.

Profile

fancms

Posted: 22 October 2007 11:33 AM

[ Ignore ] [ # 6 ]

Grad Student

Total Posts: 35

Joined 10-20-2007

Great! Thanks so much for your help!

Signature

PHP + CodeIgniter

Profile

‹‹ CodeIgniter and PayPal IPN oracle problem? ’ocifetchinto() expects parameter 1 to be resource, null given’ ? ››

Username		Remember Me?
Password		forgot password?

Post Marker Legend
	New posts	Hot Topic with new posts	New Poll	Moved Topic	Sticky topic
	No new posts	Hot Topic with no new posts	Old Poll	Closed Topic	Announcements

Visitor Statistics
The most visitors ever was 819, on March 11, 2010 11:15 AM
Total Registered Members:	120532	Total Logged-in Users:	37
Total Topics:	126594	Total Anonymous Users:	3
Total Replies:	665537	Total Guests:	378
Total Posts:	792131