ruby-on-rails - ActiveRecord::QueryMethod 'includes' 忽略了我的选择方法。我该如何处理？

Question

所以我在这里遇到了一个小问题。基本上我有两个表 - restaurants 和 inspections(restaurant 模型 has_many :inspections。我需要拉一个列表在检查中获得特定分数(在本例中为 70)的餐厅的数量。我们的想法是获取每家餐厅的所有检查。

如果我在控制台中运行以下命令...

places = Restaurant.joins(:inspections).where("zip = '78741' AND score = 70").select("name, ST_AsGeoJSON(the_geom) as gj")

...我按预期获得了餐厅列表。它返回名称和 geojson 几何图形。完美的。我怎么知道在 places 上迭代而不遇到整个 1 + N 问题。我尝试使用 includes 但这删除了编写我自己的 select 方法的能力。有什么想法吗？

来 self 的模型

InspectionModel
belongs_to :restaurant, foreign_key: :facility_id

RestaurantModel
has_many :inspections, foreign_key: :facility_id, primary_key: :facility_id

来 self 的数据库:

psql (9.3.3)
Type "help" for help.

maple_dev=# \d+ inspections
                             Table "public.inspections"
   Column    |       Type        |   Modifiers  | Storage  | Stats target | Description 
-------------+-------------------+--------------+----------+--------------+-------------
 date        | date              |              | plain    |              | 
 score       | integer           |              | plain    |              | 
 facility_id | character varying |              | extended |              | 
 description | character varying |              | extended |              | 
 id          | integer           | not null ... | plain    |              | 
Indexes:
    "inspections_pkey" PRIMARY KEY, btree (id)
    "index_inspections_on_facility_id" btree (facility_id)
Has OIDs: no

maple_dev=# \d+ restaurants
                             Table "public.restaurants"
   Column    |       Type        | Modifiers | Storage  | Stats target | Description 
-------------+-------------------+-----------+----------+--------------+-------------
 facility_id | character varying |           | extended |              | 
 name        | character varying |           | extended |              | 
 zip         | character(5)      |           | extended |              | 
 address     | character varying |           | extended |              | 
 latitude    | double precision  |           | plain    |              | 
 longitude   | double precision  |           | plain    |              | 
 the_geom    | geometry          |           | main     |              | 
Indexes:
    "index_restaurants_on_facility_id" btree (facility_id)
Has OIDs: no

Answer 1

你可以使用 ActiveRecord Association Extensions :

#app/models/restaurant.rb
Class Restaurant < ActiveRecord::Base
   has_many :inspections, foreign_key: :facility_id, primary_key: :facility_id do
       def score(zip, score)
           where("zip = ? AND score = ?", zip, score).select("name, ST_AsGeoJSON(the_geom) as gj")
       end
   end
end

这将允许您调用:

@location1 = Restaraunt.inspections.score("01456", "70")
@location2 = Restaraunt.inspections.score("15654", "80")

---

过程

1. 将“地点”设置为可变数据——目前，它是手动的
2. 使用一种方法调用所有必需的数据以满足您的规范

AR Association Extensions 是 Rails 的一项鲜为人知的功能，基本上允许您定义有关您调用的数据的细节。我不知道我的代码是否能正常工作，但它肯定会为您指明正确的方向