在MY_Model中生成一个sql字符串

I'm using Jamie Rumbelow's MY_Model to develop model's for my modules. I'm running into some issues when I'm trying to use relationships within those module model's. I'm trying to learn how to debug with this. I would like to view the SQL generated string to see what is being ran as the query. Does anybody know how to do this.

Try:

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

This will echo your last SQL query.