Join query of two databases in codeigniter

I need to write a join query of two tables from two databases and fetch the joined data.
For eg, consider I have a database db1 which has some tables named companies, plans, customers. Suppose I need to join the two tables companies and plans with another table ‘cdr’ on another database db2 by grouping them using a similar column.

Extending The Controller Class in CodeIgniter

I have class MY_Controller extends CI_Controller and common logic for big profile section, so I’va tried to create class Profile extends MY_Controller with common logic for profile section and all class related to this section should extends this Profile class as I understand right, but when I tried to create class Index extends Profile I recieve an error: