Question

I am working on codeigniter and I am writing the following query:

$this->db->select('*');
$this->db->from('tbl_profile');
$this->db->join('tbl_msg', 'tbl_msg.msg_sender_id = tbl_profile.profile_id');
$this->db->order_by("msg_id", "desc");
$query = $this->db->get('', $config['per_page'], $this->uri->segment(3));
$data['records'] = $query->result_array();

Correspondingly I am getting the following result:

SELECT (*) FROM tbl_profile
JOIN tbl_msg ON tbl_msg.msg_sender_id = tbl_profile.profile_id

Which is returninng a wrong result as I want the result corresponding to the following query:

select * from tbl_profile as A
join (select * from tbl_msg) as B on A.profile_id = B.msg_sender_id

Please help

Answer 1

First of all, you missing the order by clause, but I assum, you mean other differences.

If you want that, you can use this query, what will gave you back the exact code:

$this->db->select('*', FALSE);
$this->db->from('tbl_profile as A');
$this->db->join('( select * from tbl_msg ) as B', 'A.msg_sender_id = B.profile_id');
$this->db->order_by("msg_id", "desc");
$query = $this->db->get('', $config['per_page'], $this->uri->segment(3));
$data['records'] = $query->result_array();

From codeigniter user manual:

$this->db->select()

accepts an optional second parameter. If you set it to FALSE, CodeIgniter will not try to protect your field or table names with backticks. This is useful if you need a compound select statement.