Easy Array Question

I have part of my code where I get an array full of user_ids, sort of
like this:

@user_ids = [1,3,44,5,6]

Is there a way for me to do something like
@the users = User.find_all_by_id(@user_ids)

that will get all those users in one database call?

I have part of my code where I get an array full of user_ids, sort of
like this:

@user_ids = [1,3,44,5,6]

Is there a way for me to do something like
@the users = User.find_all_by_id(@user_ids)

That will do it (Or User.find(@user_ids), the difference is what happens if not all of the users can be found)

Fred