In Rails 5, how do I write a finder "OR" query to say exlucde from a list or be nil?

Question

I want to write a Rails 5 finder query that returns objects if a field does not belong to a certain set of values or is null. I tried the below

Order
.joins(...joins1...)
.joins(...joins2...)
.left_outer_joins(:customer => :program)
      .where.not(
        :programs => { :number => excluded_numbers }
      ).or(:programs => { :number => nil})
    .where(...)

but this results in a

ArgumentError: You have passed Hash object to #or. Pass an ActiveRecord::Relation object instead.

What is the proper way to form my "OR" clause?

Answer 1

As the error says, you must pass an ActiveRecord::Relation, right now you're passing the { :programs => { :number => nil} } hash.

Try with:

orders = Order.joins(...).joins(...).left_outer_joins(customer: :program)
orders.where.not(programs: { number: excluded_numbers })
      .or(orders.where(programs: { number: nil }))
      .where(...)

The condition for or to work is that the two relations must be structurally compatible, so, both must include the joins and left_outer_joins you're using. That's the purpose of storing them in a local variable.