Rails:HasManyThroughAssociationNotFoundError

Question

我有一个has_many through关联工作的问题.

我一直得到这个例外:

Article.find(1).warehouses.build
ActiveRecord::HasManyThroughAssociationNotFoundError: Could not find the association :entries in model Article

这些是涉及的模型:

class Article < ActiveRecord::Base
  has_many :warehouses, :through => :entries
end

class Warehouse < ActiveRecord::Base
  has_many :articles, :through => :entries
end

class Entry < ActiveRecord::Base
  belongs_to :article
  belongs_to :warehouse
end

这是我的架构:

create_table "articles", :force => true do |t|
  t.string   "article_nr"
  t.string   "name"
  t.integer  "amount"
  t.string   "warehouse_nr"
  t.datetime "created_at"
  t.datetime "updated_at"
  t.integer  "unit"
end

create_table "entries", :force => true do |t|
  t.integer "warehouse_id"
  t.integer "article_id"
  t.integer "amount"
end

create_table "warehouses", :force => true do |t|
  t.string   "warehouse_nr"
  t.string   "name"
  t.integer  "utilization"
  t.datetime "created_at"
  t.datetime "updated_at"
end

Answer 1

你需要添加

has_many :entries

对于每个模型,由于:through选项只指定了第二个关联,它应该用于查找另一侧.

Answer 2

你需要添加

has_many :entries

对于每个模型，以及上面的 has_many :through，就像这样：

class Article < ActiveRecord::Base
  has_many :entries
  has_many :warehouses, :through => :entries
end

class Warehouse < ActiveRecord::Base
  has_many :entries
  has_many :articles, :through => :entries
end

关于如何处理视图和控制器的更详细教程https://kolosek.com/rails-join-table/