包含在我的模型中"has_many"但我遇到了"ActiveRecord::HasManyThroughAssociationNotFoundError"错误

Question

我正在使用Rails 5.1。 我对如何创建一个模型和关联感到困惑，其中我有一个链接两个模型的连接表。 下面是我的两个表的 PostGres 连接表......

mydb=# d organization_workers;
                               Table "public.organization_workers"
      Column       |  Type   |                          Modifiers
-------------------+---------+--------------------------------------------------------------
 id                | integer | not null default nextval('organization_workers_id_seq'::regclass)
 organization_id        | integer |
 stratum_worker_id | integer |

然后我这样定义模型

class Organization < ApplicationRecord
  has_many :stratum_workers, :through => :organization_workers

class OrganizationWorker < ApplicationRecord
  belongs_to :organization
  belongs_to :stratum_worker
end

但是当我运行引用的测试

assert_false organization.stratum_workers.empty?, "A pre-condition of this test is thta the org have stratum workers."

我收到错误

Error:
OrganizationTest#test_Test_total_paid:
ActiveRecord::HasManyThroughAssociationNotFoundError: Could not find the association :organization_workers in model Organization
    test/models/organization_test.rb:7:in `block in <class:organizationTest>'

Answer 1

您需要首先为连接表本身定义一个has_many，然后才能定义through关联。否则，Rails将不知道在哪里寻找弥合差距。

联接模型看起来正常。但是您要加入的模型应如下所示：

class Organization < ApplicationRecord
  has_many :organization_workers
  has_many :stratum_workers, through: :organization_workers
end

class StratumWorker < ApplicationRecord
  has_many :organization_workers
  has_many :organizations, through: organization_workers
end