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我有一个模型,我正在使用awesome_nested_set
插件在分层组织中跟踪权限。我遇到了一个问题,其中两个named_scope
链接在一起时正在创建一个复制INNER JOIN
。这些named_scopes为什么会导致重复的INNER JOIN?
class Group < ActiveRecord::Base
acts_as_nested_set
has_many :memberships
has_many :accounts, :through => :memberships
has_many :authorizations
has_many :users, :through => :authorizations
end
两个named_scope
s的位于所述Account
模型,和用于过滤由一个用户帐户和由一组:
named_scope :in_group, lambda { |id|
group_ids = Group.find(id).self_and_descendants.collect(&:id)
{ :joins => :memberships, :conditions => ["memberships.group_id in (?)", group_ids] }
}
named_scope :for, lambda { |user|
groups = user.authorizations.groups.collect(&:id) unless user.admin?
user.admin ? {} : { :joins => :groups, :conditions => ["groups.id IN (?)", groups] }
}
这两种named_scope
的需要加入memberships
,但他们不应该能够做到这一点没有重复?当它们链接在一起,MySQL的吹了以下错误:
Mysql::Error: Not unique table/alias: 'memberships': SELECT `accounts`.* FROM `accounts` INNER JOIN `memberships` ON accounts.id = memberships.account_id INNER JOIN `memberships` ON `accounts`.`id` = `memberships`.`account_id` INNER JOIN `groups` ON `groups`.`id` = `memberships`.`group_id` WHERE ((memberships.group_id in (54,94)) AND (groups.id IN (54,94))) ORDER BY business_name, location_name LIMIT 0, 75
您是否尝试将'for'命名范围中的连接语句更改为':joins => {:memberships =>:groups}?我怀疑has_many通过关系可能会导致它。 – 2010-07-09 19:03:44
DUH! ''我应该看到那个。谢谢!你应该添加一个答案,以便我可以标记它。 –
2010-07-09 19:26:11
很高兴为你效劳 – 2010-07-09 19:29:50