glebtv/the_sortable_tree — comment on commit 0fc578e6f674309cdb2c1db5289f41ce1f314ebd
File:  line 0
By the-teacher:

scope :nested_set, order_by(:lft => :asc)
scope :reversed_nested_set, order_by(:lft => :desc)

I like it. I will try to use it