Question

我有以下三个模型

LegacyRole：

class LegacyRole < LegacyModel
  has_many :permissions_roles
  has_many :permissions, :through => :permissions_roles
end

LegacyPermissionsRole：

class LegacyPermissionsRole < LegacyModel
  belongs_to :role
  belongs_to :permission
end

和LegacyPermission：

class LegacyPermission < LegacyModel
  has_many :permissions_roles
  has_many :roles, :through => :permissions_roles
end

为了使这些工作全部工作，并连接遗留数据库和诸如此类的东西，我有以下类LegacyModel可能试图太聪明......

require 'active_record'

class LegacyModel < ActiveRecord::Base
  self.abstract_class = true

  establish_connection "legacy_#{::Rails.env}"

  def self.inherited(subclass)
    tabeleized_name = subclass.name.tableize
    raise "Legacy models must be prefixed with 'Legacy'" unless tabeleized_name.start_with?('legacy_')

    logger.info "***********LOAD***********"
    logger.info "Loaded legacy model: #{subclass.name} using table: #{tabeleized_name.gsub('legacy_', '')}"
    super
    subclass.set_table_name tabeleized_name.gsub('legacy_','')
  end


  # these methods do much the same thing, can probably abstract some of this out
  def self.belongs_to(association_id, options = {})
    new_association = association_id.to_s.insert(0, 'legacy_').to_sym
    old_association = association_id


    logger.info "Legacy model has belongs_to association: '#{association_id}'"
    association_id = association_id.to_s.insert(0, 'legacy_').to_sym
    logger.info "Converting association to: '#{association_id}'"

    unless options.has_key?(:foreign_key)  
      # our foreign_key is missing
      options[:foreign_key] = old_association.to_s.foreign_key
      logger.info("Foreign_key was missing, is now: #{options[:foreign_key]}")
    end

    super
    alias_method old_association, new_association
  end

  def self.has_many(association_id, options = {})
    new_association = association_id.to_s.insert(0, 'legacy_').to_sym
    old_association = association_id


    logger.info "Legacy model has_many to association: '#{association_id}'"
    association_id = association_id.to_s.insert(0, 'legacy_').to_sym
    logger.info "Converting association to: '#{association_id}'"
    logger.debug("Association options are: #{options.inspect}")

    if options.has_key?(:through)
      options[:through] = options[:through].to_s.insert(0, 'legacy_')
      logger.info("Through mutated, is now: #{options[:through]}")
    end

    super
    alias_method old_association, new_association
  end

end

每当我尝试访问LegacyRole实例的权限时，我都会收到以下Active Record错误： ActiveRecord :: HasManyThroughAssociationNotFoundError：在模型LegacyRole中找不到关联“legacy_permissions_roles”

我尽可能地完成了这一切，我真的无法弄清楚为什么会发生这种情况，显然这比LegacyModel类的标准要复杂得多，我真的不知道如何诊断这进一步......我现在正处于这样的地步，在那里我看不到森林的树木，觉得它可能只是一些非常简单的东西我错过了！

修改

以下是模型加载的日志输出

****************************
Loaded legacy model: LegacyPermission using table: permissions
Legacy model has_many association: 'permissions_roles'
Converting association to: 'legacy_permissions_roles'
Association options are: {}
Legacy model has_many association: 'roles'
Converting association to: 'legacy_roles'
Association options are: {:through=>:permissions_roles}
Changed :through to: 'legacy_permissions_roles'

****************************
Loaded legacy model: LegacyPermissionsRole using table: permissions_roles
Legacy model has belongs_to association: 'role'
Converting association to: 'legacy_role'
Legacy model has belongs_to association: 'permission'
Converting association to: 'legacy_permission'
Foreign_key was missing, is now: 'permission_id'

****************************
Loaded legacy model: LegacyRole using table: roles
Legacy model has_many association: 'permissions_roles'
Converting association to: 'legacy_permissions_roles'
Association options are: {}
Legacy model has_many association: 'permissions'
Converting association to: 'legacy_permissions'
Association options are: {:through=>:permissions_roles}
Changed :through to: 'legacy_permissions_roles'

Answer 1

也许你想要

class LegacyRole < LegacyModel
  has_many :permissions_roles
  has_many :permissions, :through => :legacy_permissions_roles # note the `legacy` prefix
end

或者这是你帖子中的拼写错误？

ActiveRecord :: HasManyThroughAssociationNotFoundError问题，有一个扭曲

1 个答案: