Question

The following code is issuing the following error message:

A Database Error Occurred
Error Number: 1066
Not unique table/alias: 'users'

SELECT * FROM (`users`, `users`) JOIN `user_profiles` ON `users`.`id` = `user_profiles`.`user_id`

Filename: /home/xtremer/public_html/kowmanager/models/cpanel/dashboard.php

Line Number: 38

Here is my code:

class Dashboard extends CI_Model {
  private $table_name = 'users'; // user accounts
  private $profile_table_name = 'user_profiles'; // user profiles

  function __construct() {
    parent::__construct();
    $ci =& get_instance();
    $this->table_name = $ci->config->item('db_table_prefix', 'tank_auth').$this->table_name;
    $this->profile_table_name = $ci->config->item('db_table_prefix', 'tank_auth').$this->profile_table_name;
  }

 /**
  * Get user info by Id
  *
  * @param int
  * @param bool
  * @return object
  */
  function get_user_info($id) {
    $this->db->select('*');
    $this->db->from('users');
    $this->db->join('user_profiles', 'users.id = user_profiles.user_id');

    $query = $this->db->get($this->table_name);
    if ($query->num_rows() == 1) {
      return $data = $query->row();  
    }  else {
     return NULL;  
    }
  }
}

EDIT: I know have this for my function and changed it because after looking at it I didn’t need the extra table. I have an array ($data) of values being sent to my header but can I get away with sending it to the build that way it sends the array to all the partials.

function get_user_info($id)
{
    $this->db->select('*');
    $this->db->from('users');
    $this->db->where('users.id', $id);

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

    if ($query->num_rows() == 1) 
    {
        return $data = $query->row();    
    }
    else 
    {
        return NULL;    
    }

}   

And this is from my controller I updated:

function index()
{
    $id = $this->tank_auth->get_user_id();

    $data = $this->Dashboard->get_user_info($id);
    print_r($data);
    $this->template->set_layout('cpanel')->enable_parser(false);
    $this->template->set_partial('header', 'partials/header', $data);  
    $this->template->set_partial('sidebar', 'partials/sidebar');  
    $this->template->set_partial('content', 'partials/content');      
    $this->template->set_partial('footer', 'partials/footer');
    $this->template->build('/cpanel/index');
}

Answer 1

The problem is this:

SELECT * FROM (users, users)

I assume you’re trying to join the table to itself, but you can’t do that without giving aliases to the tables, otherwise the database doesn’t know which side of the join you’re referring to when you reference fields from it.

Try this:

SELECT * 
FROM users u1, users u2 
JOIN user_profiles ON u1.id = user_profiles.user_id

Update:

My above answer was written based on the error message, but I didn’t notice the code link (I’ve since added the code to be inline with the question).

I’m not overly familiar with CI, but I have a feeling your problem lies in these three lines:

1. private $table_name = 'users';
2. $this->db->from('users');
3. $query = $this->db->get($this->table_name);

In line 3, you’re explicitly getting $this->table_name which points to the users table as shown in line 1). However, by explicitly setting a from table, also pointed to users, in line 2, I think you’re accidentally setting up a join between two tables. Since these two tables are both the same, and neither is aliased, it is resulting in an error. Try removing the $this->db->from('users'); line and seeing if that resolves the issue.

Update 2:

I’ve been reading the CodeIgniter user guide, and it seems you don’t need to specify anything as a parameter to $this->db->get() when you’re using building a query using methods like from(). I’d suggest just changing this line:

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

to this:

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

See this page for details.