范围不接收数组作为参数

Question

我在模型中定义了以下范围：

  scope :answers_in, -> (answers = nil) do
    return unless answers.present?
    where(answer_1: answers).or(where(answer_2: answers))
  end

answers应该由一个数组组成。但是，当我发出传递数组的调用时，会收到一个参数错误：

AnswerConnection.answers_in([1, 2])
ArgumentError: wrong number of arguments (given 2, expected 0..1)
        from /vagrant/farma_alg_reborn/app/models/answer_connection.rb:7:in `block in <class:AnswerConnection>'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/scoping/named.rb:159:in `instance_exec'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/scoping/named.rb:159:in `block (2 levels) in scope'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/relation.rb:351:in `scoping'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/scoping/named.rb:159:in `block in scope'
        from (irb):2
        from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/console.rb:65:in `start'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/console_helper.rb:9:in `start'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:78:in `console'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands.rb:18:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:293:in `require'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:293:in `block in require'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:293:in `require'
        from /vagrant/farma_alg_reborn/bin/rails:9:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:287:in `load'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:287:in `block in load'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:287:in `load'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/commands/rails.rb:6:in `call'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/command_wrapper.rb:38:in `call'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:191:in `block in serve'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:161:in `fork'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:161:in `serve'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:131:in `block in run'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:125:in `loop'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:125:in `run'
        from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application/boot.rb:19:in `<top (required)>'
        from /usr/local/rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
        from /usr/local/rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
        from -e:1:in `<main>'

这是一个bug，Rails作用域不适用于数组，还是我做错了什么？

Answer 1

您必须在or方法中加入一个参数。试试这个：

where(user_1: answers).or(where(user_2: answers))

UPDATE (ArgumentError:参数数错误)

不能为作用域设置默认参数值：

scope :answers_in, -> (answers = nil) do

因此，将其替换为：

scope :answers_in, -> (answers) do

或者，如果希望参数是可选的，请定义如下范围：

scope :answers_in, -> (*answers) do

但是，您必须将数组元素作为分隔参数AnswerConnection.answers_in(1, 2)传递，而不是AnswerConnection.answers_in([1, 2])。