Question

Working with the following code, I need to return only records where the `point’ attribute is unique. I can’t seem to get there by myself.

uniques = Item.find_all_by_item_id(item_id) uniques.sort! {|a, b| b.point <=> a.point } # how do I reject the equal points? 

In other words.. I guess, how do you make [0, 1, 1, 1, 2, 3, 3, 4, 4, 7] #=> [0, 2, 7] ?

Answer 1

How about this:

# Get the number of items with each point value counts = Item.count('point', :group => 'point')  # Get the IDs of all entries that only show up once unique_ids = counts.collect { |count| count[0] if count[1] == 1 }.compact  unique_items = Item.find_all_by_id(unique_ids)