Converting MYSQL to Codeigniter - mysql

Question

I am trying to convert a MYSQL query to codeigniter and going no wheres real fast. I am trying to convert this query
$conn->prepare("SELECT `id`,`song`,`artist`,`album`,`track`,`mix_name`,`date` FROM `podcasts` where mix_number = (SELECT MAX(mix_number) FROM podcasts) order by track asc");
This is in my model:
//$where = '(SELECT MAX(mix_number)from podcasts)';
$this->db->select('id,song,artist,album,track,mix_name,date, link');
//$this->db->where('mix_number', '(SELECT MAX(mix_number)from podcasts)');
$this->db->order_by('track', 'asc');
$query = $this->db->get('podcasts');
return $query->result();
My problem area is in the where statement. When I comment out the where statement I get the data. Obviously not in the manner I want it.
I am doing it this way becuase my next query(s) will be
("SELECT `id`,`song`,`artist`,`album`,`track`,`mix_name`,`date` FROM `podcasts` where mix_number = **(SELECT MAX(mix_number) FROM podcasts) - 1** order by track asc")
And on down to (SELECT MAX(mix_number) FROM podcasts) - 3
Any thoughts on the proper way of writing the where statement? Thank you for yout time.

Answer 1

Set the third argument of where() to false to prevent CI from altering the string you pass in to the second argument, then you can do the subquery:
return $this->db
->select('id,song,artist,album,track,mix_name,date, link')
->where('mix_number', '(SELECT MAX(mix_number) from podcasts)', false)
->order_by('track', 'asc')
->get('podcasts')
->result();
https://www.codeigniter.com/userguide2/database/active_record.html$this->db->where() accepts an optional third parameter. If you set it to FALSE, CodeIgniter will not try to protect your field or table names with backticks.
For me this produces the following query:
SELECT `id`, `song`, `artist`, `album`, `track`, `mix_name`, `date`, `link`
FROM (`podcasts`)
WHERE mix_number = (SELECT MAX(mix_number) from podcasts) ORDER BY `track` asc

Answer 2

If you are not too particular about using CodeIgniter's Active Record syntax, you can simply use your query as is:
$sql = "SELECT `id`,`song`,`artist`,`album`,`track`,`mix_name`,`date` FROM `podcasts` where mix_number = (SELECT MAX(mix_number) FROM podcasts) order by track asc";
$this->db->query($sql);
and then use $query->result() to get your results.