<% purchase_scope = @purchase.product.purchases.completed purchase_ids = Array(session[:purchase_id]) customer_ids = Customer.where(user_id: current_user.id, account_id: Account.current.id).pluck(:id) if current_user # This can be a slow query if we allow it to do id IN (NULL). existing_purchases = if purchase_ids.present? && customer_ids.present? purchase_scope.where("purchases.id IN (?) OR customer_id IN (?)", purchase_ids, customer_ids) elsif purchase_ids.present? purchase_scope.where(purchases: { id: purchase_ids }) elsif customer_ids.present? purchase_scope.where(customer_id: customer_ids) else Purchase.none end