What next after SQL fundamentals?

Question

I completed sololearn SQL course which I feel is very much basic.
I want to gain more SQL knowledge in sub-queries,procedures,Triggers,Functions,Transactions and batches.
What books or sites you guys recommend for having these things clear?
Thanks in Advance.

Answer 1

Read this:
https://books.goalkicker.com/SQLBook/

note : I got it from a post in Sololearn but i couldn't find the post any more

Answer 2

Thanks a lot !!