It is its own dialect. But for example you can do things like:
select from table where date <= x;
select avg vlm by date from dailytrade;
delete from table where sym= x;
However one big difference is that update and delete work on both columns and rows, and that most of the operators reside within the language itself and extend beyond just tables, i.e., one can use intersection, within, in, except (set minus) using the generic data constructs of the language.
It is a relational algebra system built on top of a fully featured programming language. I hope to see more languages like this in the future (the Dee project for Python is supposed to be doing something similar).
I was going to take a class next semester that covers half VBA half SQL. But after seeing this thread, I am wondering if I should take the database course that covers SQL more thoroughly and learn VBA on my own. What do you think?