How to nominate a limit and an offset parameter with CodeIgniter's limit()?

I am very new to codeigniter and try to write a simple blog app:

controller: posts.php

class Post extends CI_Model {
    
    function get_posts($num = 20, $start = 0) {
       $this->db->select()->from('posts')->where('active', 1)->order_by('date_added', 'dec')->limit(0, 20);
        $query = $this->db->get('posts');
        return $query->result_array();
    }
}

Model: post.php

class Posts extends CI_Controller {
    function index() {
        $this->load->model('post');
        $data['posts'] = $this->post->get_posts();
        echo"<pre>";print_r($data['posts']);echo"</pre>";
    }
}

I have populated posts table in the database. However when I try to get results I get this instead:

Array
(
)

mysql> describe posts;

+------------+--------------+------+-----+-------------------+-----------------------------+
| Field      | Type         | Null | Key | Default           | Extra                       |
+------------+--------------+------+-----+-------------------+-----------------------------+
| postID     | int(10)      | NO   | PRI | NULL              | auto_increment              |
| title      | varchar(255) | NO   |     | NULL              |                             |
| post       | text         | NO   |     | NULL              |                             |
| date_added | timestamp    | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| userID     | int(4)       | NO   |     | NULL              |                             |
| active     | tinyint(1)   | NO   |     | NULL              |                             |
| slug       | varchar(255) | NO   |     | NULL              |                             |
+------------+--------------+------+-----+-------------------+------------------

What's wrong with this code and how can I fix it?

Because your query is getting wrong as you already have ->from('posts') so you dont need the table name any more in get

Change

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

With

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

And

->order_by('date_added','desc')