Get total count for use with pagination for MySQL

gistfile1.php

//if your query is raw sql you created, each mysql key word must be on a new line for this to work
$last_query = $this->db->last_query();
$pattern = '/(.*)Limit (.*)/i';
$new_query = preg_replace ($pattern, '', $last_query);

$pattern = '/(.*)Select *(.*)/i';
$new_query = preg_replace ($pattern, 'SELECT \'\'', $new_query);

$new_query = 'Select Count(*) AS res From (' . $new_query . ') v__dynamic;';

$query = $this->db->query($new_query);
$result = $query->row();