advance in sql

Question

if someone could please advise me how to go further in learning sql

Answer 1

I recommend to take Oracle SQL Expert certification if you wish to go further.

Answer 2

You can check their website below:
Hope you find it useful

http://education.oracle.com/pls/web_prod-plq-dad/db_pages.getpage?page_id=786

Answer 3

but any suggestions where i could learn this online