我有一些这样的模型类:
class Organisation < ActiveRecord::Base
has_many :dongles
has_many :licences_on_owned_dongles, :through => :dongles, :source => :licences,
:include => [:organisation, :user, :owner_organisation, :profile, :dongle,
{:nested_licences => [:profile]} ]
end
class Dongle < ActiveRecord::Base
has_many :licences
belongs_to :organisation
end
class Licence < ActiveRecord::Base
belongs_to :dongle
# tree-like structure. I don't remember why this had to be done but the comment says
# "find a way to make the simpler way work again" and I tried using the simpler way
# but tests still fail. So obviously the SQL awfulness is necessary...
default_scope :conditions => { :parent_licence_id, nil }
has_many :nested_licences, :class_name => 'Licence', :dependent => :destroy,
:autosave => true,
:foreign_key => :parent_licence_id,
:finder_sql => proc {
"SELECT l.* FROM licences l WHERE l.parent_licence_id = #{id}" },
:counter_sql => proc {
"SELECT COUNT(*) FROM licences l WHERE l.parent_licence_id = #{id}" }
end
现在我可以这样做了:
test "getting licences on owned dongles" do
org = organisations(:some_other_corp)
assert_equal [licences(:licence_4)], org.licences_on_owned_dongles
end
就这样愉快地过去了。既然它是一个协会,你可能会觉得你可以find()
:
test "getting licences on owned dongles and then filtering further" do
org = organisations(:some_other_corp)
conditions = { :owner_organisation_id => nil }
assert_equal [licences(:licence_4)],
org.licences_on_owned_dongles.find(:all, :conditions => conditions)
end
但这给出了:
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: dongles.organisation_id: SELECT "licences".* FROM "licences" WHERE "licences"."parent_licence_id" IS NULL AND (("dongles".organisation_id = 72179513)) AND ("licences".parent_licence_id = 747059259)
test/unit/organisation_test.rb:123:in `test_getting_licences_on_owned_dongles_and_then_filtering_further'
事实上,这甚至发生在您调用的所有内容都是find(:all)
. 它也不仅仅是 SQLite,因为我在 MySQL 的生产(oops)中注意到了这一点。
所以我不知道。实在是太玄乎了,无法深入调查。我可能会将其搁置为“Rails 无法在关联上执行 find()”,使用块对其进行过滤并将其保留。但我想把它拿出来,以防万一有更好的选择。
(实际上,如果您查看 Rails 正在生成的查询,那完全是胡说八道。不知何故,它最终生成了一个查询,其中必须同时为 NULL 和等于一个值。即使查询有效,这也会返回0 行。)