问合并ActiveRecord_Relation

EN

在模型横幅中

belongs_to :segment
belongs_to :basic_component
has_many :state_banners, dependent: :destroy
has_many :states, through: :state_banners

scope :banner_have_zero_cities, lambda { includes(state_banners: :state_banner_cities).where(state_banner_cities: {state_banner_id: nil}) }
scope :banner_by_state, lambda { |state_id| where("state_banners.state_id = ?", state_id) }
scope :banner_by_city, lambda { |city_id| joins(state_banners: :state_banner_cities).where("state_banner_cities.city_id = ?", city_id) }

在控制器中

def scoped_collection
   @banners_cities = Banner.banner_by_city(city_id)
   @banners_states =Banner.banner_by_state(city.state_id).banner_have_zero_cities
   @banners = @banners_cities.concat(@banners_states)
   return @banners.joins(:basic_component)
 end

@banners_states.size => 1

@banners_cities.size => 2

@banners_states.merge(@banners_cities) SQL (0.2ms) SELECT DISTINCT banners。id FROM banners INNER JOIN state_banners ON state_banners。banner_id=banners。id INNER JOIN state_banner_cities ON D11。D12=D13。D14 WHERE (state_banners.state_id = 3) AND D15。D16为NULL且(state_banner_cities.city_id = '260') LIMIT 25 OFFSET 0 => []

我需要3个

我尝试concat

@banners = @banners_cities.concat(@banners_states) @banners.size => 3

但

@banners.joins(:basic_component).order("basic_component.order asc").size => 2

缓存(0.0ms) SELECT COUNT( count_column ) FROM (SELECT 1 AS count_column FROM banners INNER JOIN state_banners ON state_banners.banner_id = banners.id INNER JOIN state_banner_cities ON state_banner_cities.state_banner_id =D26.D27 INNER JOIN D29上的D28。D30=D31.D32 WHERE (state_banner_cities.city_id = '260') LIMIT 25 OFFSET 0) subquery_for_count

:(，帮助