Message: Undefined property: $db

I included this line in my controller.

Code:

$countusername = count($this->db->query("SELECT * FROM users WHERE username = '$_POST[username]'")->result_array()); 

And I get this error.

Message: Undefined property: Makenew::$db

Why? I configured my database correctly.

You need to autoload it or load it manually
https://www.codeigniter.com/user_guide/d...cting.html

and

database request should be in the model