if my category_id could be either nil or a int value, how can I specify
a condition that handles both?
conditions => ["parent_id = ?",params[:category_id]]
conditions => ["parent_id is ?",params[:category_id]]
I'm using acts_as_tree which meets the root levels have no parent_id
(null in SQL)
so if no category_id is passed as a parameter I want it to pull up the
roots, if one is passed, I want it to pull the children of that node.