在codeigniter中的join语句中应用条件

Question

I am facing a problem with my codeigniter mysql query. The problem is i want to introduce a if condition on join statement, If that join doesn't return data then join another table. for example :

$this->db->select(*);
if(!$this->db->join(XYZ,XYZ.id=abc.id)){
   $this->db->join(PQR,PQR.id=abc.id)
}

I want something like this, Is there any way to apply this approach. Thanks

Answer 1

Take reference of my example,it may help you out

$this->db->select(*);
$this->db->set('tbl1.user_time_index', "CASE WHEN tbl1.status = 'OK' THEN tbl1.emp_time_index ELSE tbl2.user_time_index END", FALSE);
$this->db->where('tbl1.user_id', 100);

Here CASE statement is used which works as if{}else{} statement