Cfrgtkky

I have a collection of books. In my view I want to show a random sample of 5 books from the top 10 bestselling books in my DB. However, I only want a maximum of ONE non-fiction title (book.genre) showing in that sample. It's ok if no non-fiction books are sampled.

Controller:

def index 

  @top_selling_books = Book.all.order('units_sold DESC').first(10).sample(5)

end

View:

<% @top_selling_books.each.with_index(1) do |book, index| %>

  <div>

    <%= render "books/top_sellers", book: book, index: index %>

  </div>

<% end %>

If you want to do complicated results, sometimes it's best not to do it all in one query. It can be much harder to maintain than simple logic. However, there is definitely a balance to maintainability, scalability, and performance.

I would suggest doing something like this:

def top_books(limited_genres: )

  non_limited_books = Book.where.not(genre: limited_genres).order('units_sold DESC').first(10).sample(5)

  limited_books = Book.where(genre: limited_genres).order('units_sold DESC').first(5).sample(1) # rename to limited_book if sample is kept to 1

  (top_books + limited_books).sort_by(:units_sold)[0..5]

end



@top_selling_books = top_books(limited_genres: ['non-fiction'])

This is non tested code. It's just to give you an idea on how to accomplish your goals.