Question

我正致力于在Ruby on Rails应用程序中创建问卷数据模型，该应用程序需要复合主键和外键。对于此任务，我使用composite-primary-keys gem与SQLServer，我过去使用的配对。不幸的是，当我使用复合进行查找时遇到问题，无论是指定.find（[x，y，z]），还是使用belongs_to关系定义的方法。 有趣的是，但是，它通过has_many定义的关系正常运行。我的模型如下（错误将在本文的底部）：

class QuestionSet < ActiveRecord::Base
  self.primary_keys = :question_set_id, :generation, :language_id
  has_many :question_set_questions,
      foreign_key: [:set_id, :set_generation],
      primary_key: [:question_set_id, :generation]
  has_many :questions, through: :question_set_questions
end

class QuestionSetQuestion < ActiveRecord::Base
  belongs_to :question_set,
      -> { where :language_id => Language.current_language.id },
      foreign_key: [:set_id, :set_generation],
      primary_key: [:question_set_id, :generation]
  belongs_to :question,
      -> { where :language_id => Language.current_language.id },
      foreign_key: [:question_id, :question_generation],
      primary_key: [:question_id, :generation]
end

class Question < ActiveRecord::Base
  self.primary_keys = :question_id, :generation, :language_id
  has_many :question_set_questions,
      foreign_key: [:question_id, :question_generation],
      primary_key: [:question_id, :generation]
  has_many :question_sets, through: :question_set_questions
end

如果模型需要解释，QuestionSet和Question每个都有一个复合主键，由三个整数组成：question_或question_set_ id，generation和language_id。它们受QuestionnaireSetQuestion约束，其中包含id和分组编号，并使用当前选定的语言（通过Language.current_language.id）来实现正确的记录。

什么有用？

如果我说的话：

qs = QuestionSet.first
qs.questions

然后一切都很完美，我看到了我期望的确切结果。我已经对此进行了非常彻底的测试，很多问题，很多问题集，很多语言，很多分组。在QuestionSet上调用.questions非常有效。它也是相反的方式，... ...

q = Question.first
q.question_sets

...每次都返回正确的结果。

此外，在问题或问题集上调用.question_set_questions可以正常运行。

什么不起作用？

如果我说......

qsq = QuestionSetQuestion.first
qsq.question
# or
qsq.question_set

......我收到错误。当我说：

时，我得到同样的错误

Question.find([1,1,1])
# or
QuestionSet.find([1,1,1])

该错误如下：

EXEC sp_executesql N'SELECT  [questions].* FROM [questions] WHERE ([questions].[question_id] = @0 AND [questions].[generat
ion] = @1 AND [questions].[language_id] = @2)  ORDER BY [questions].[question_id,generation,language_id] ASC OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY',
 N'@0 int, @1 int, @2 int', @0 = 1, @1 = 1, @2 = 1  [["question_id", 1], ["generation", 1], ["language_id", 1]]
TinyTds::Error: Invalid column name 'question_id,generation,language_id'.: EXEC sp_executesql N'SELECT  [questions].* FROM [questions] WHERE ([ques
tions].[question_id] = @0 AND [questions].[generation] = @1 AND [questions].[language_id] = @2)  ORDER BY [questions].[question_id,generation,langu
age_id] ASC OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY', N'@0 int, @1 int, @2 int', @0 = 1, @1 = 1, @2 = 1
ActiveRecord::StatementInvalid: TinyTds::Error: Invalid column name 'question_id,generation,language_id'.: EXEC sp_executesql N'SELECT  [questions]
.* FROM [questions] WHERE ([questions].[question_id] = @0 AND [questions].[generation] = @1 AND [questions].[language_id] = @2)  ORDER BY [question
s].[question_id,generation,language_id] ASC OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY', N'@0 int, @1 int, @2 int', @0 = 1, @1 = 1, @2 = 1
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:336:in `each'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:336:in `handle_to_names_and_values_dblib'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:325:in `handle_to_names_and_values'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:300:in `_raw_select'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:295:in `block in raw_select'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract_adapter.rb:466:
in `block in log'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activesupport-4.2.0/lib/active_support/notifications/instrumenter.rb:20:in `instr
ument'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract_adapter.rb:460:
in `log'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:295:in `raw_select'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:244:in `sp_executesql'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:19:in `exec_query'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-sqlserver-adapter-4.2.3/lib/active_record/connection_adapters/sqlser
ver/database_statements.rb:199:in `select'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/database_statem
ents.rb:32:in `select_all'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/query_cache.rb:
70:in `select_all'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/querying.rb:39:in `find_by_sql'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/relation.rb:638:in `exec_queries'
... 1 levels...
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/relation.rb:243:in `to_a'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/relation/finder_methods.rb:487:in `find_take
'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/relation/finder_methods.rb:105:in `take'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/composite_primary_keys-8.1.0/lib/composite_primary_keys/relation/finder_methods.r
b:124:in `find_one'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/composite_primary_keys-8.1.0/lib/composite_primary_keys/relation/finder_methods.r
b:97:in `find_with_ids'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.2.0/lib/active_record/relation/finder_methods.rb:71:in `find'
        from c:in `find'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/composite_primary_keys-8.1.0/lib/composite_primary_keys/core.rb:26:in `find'
        from (irb):1
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-4.2.0/lib/rails/commands/console.rb:110:in `start'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-4.2.0/lib/rails/commands/console.rb:9:in `start'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-4.2.0/lib/rails/commands/commands_tasks.rb:68:in `console'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-4.2.0/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-4.2.0/lib/rails/commands.rb:17:in `<top (required)>'
        from bin/rails:4:in `require'
        from bin/rails:4:in `<main>'irb(main):

对不起，这太乱了。我相信正确的重点是

TinyTds::Error: Invalid column name 'question_id,generation,language_id'

据我所知，它试图找到一个名为＆＃39; question_id，generation，language_id＆＃39;的实际列，并且因为显然没有这样的列存在而失败。我怀疑其他命令工作的原因是因为他们在这三个字段中构建了一个.where语句，而这是滥用.find。也就是说，我只是根据我观察到的行为进行推测。

如果有人对此有任何想法，我会非常感激，因为这被证明是一个重要的时间点，我还没有找到任何东西。

谢谢！

Answer 1

我对一个没有在数据库中定义主键的表有同样的问题。我在这里创建了一个问题 - https://github.com/composite-primary-keys/composite_primary_keys/issues/316 - 并且还发布了一个对我有用的修补程序。

Rails 4复合键返回无效的列名错误

什么有用？

什么不起作用？

1 个答案: