On has_and_belongs_to_many relationships you can use the :uniq option to ensure that duplicate records in the association table don't generate duplicate ActiveRecord objects when you traverse the relationship.
Is there any way to achieve the same effect when using a has_many :through relationship?
I can use:
has_many :things, :through => :assocation_table, :select => 'DISTINCT things.*'
but that then precludes the use of :include when doing a find on the relationship.