How to print SQL statement in codeigniter model

I have a sql statement in my model,

I then say

$query = $this->db->query($sql, array(fields, fields1);

if ($query) {
    return true:
} else {
    echo "failed";
    return false;
}

My query always fails, how do I get php to print the exact sql statement being sent to my database? And display that on my php view, page

Answer

To display the query string:

print_r($this->db->last_query());    

To display the query result:

print_r($query);

---

The Profiler Class will display benchmark results, queries you have run, and $_POST data at the bottom of your pages. To enable the profiler place the following line anywhere within your Controller methods:

$this->output->enable_profiler(TRUE);

Profiling user guide: https://www.codeigniter.com/user_guide/general/profiling.html