ActiveRecord OR Query in Arel

Question

For simple queries, OR queries are possible in ActiveRecord like this:

Model.where({:category => "XYZ", :item_id => some_ids})
=>
table = Model.arel_table
Model.where(table[:category].eq("XYZ").or(table[:item_id].in(some_ids)))

The result is not very compact and clear. What if you have more complex queries, is it possible and useful to write the following ActiveRecord query in Arel as well?

Model.where(["(item_id = ? AND item_type = 'ABC') OR 
              (item_id IN (?) AND item_type = 'XYZ')",id,more_ids]).
      order("created_at DESC")

Answer 1

How about:

first_part = arel_table[:item_id].eq(id).and(arel_table[:item_type].eq('ABC'))
second_part = arel_table[:item_id].in(more_ids).and(arel_table[item_type].eq('XYZ'))    

Model.where(first_part.or(second_part)).order(created_at: :desc)