Question

我在尝试提交记录时收到ActiveRecord :: AssociationTypeMismatch错误。

主题（＃88982676）预期，得到字符串（＃20223000）

查看：

<%= f.collection_select :subject, Subject.order(:subject), :subject, :subject, {prompt: "Select a subject"}, {class: "form-control"} %>

控制器：

 def create
            @homework = current_user.homeworks.build(homework_params)
            if @homework.save
                redirect_to homeworks_path
            else
                render 'new'
            end
        end
...

def homework_params
            params.require(:homework).permit(:subject, :description, :date, :completed_at)
        end

模型：Homework.rb

class Homework < ActiveRecord::Base

 validates :subject, presence:true

    belongs_to :subject

def completed?
    !completed_at.blank?
end


end

subject.rb中

class Subject < ActiveRecord::Base

     has_many :homeworks

     def to_s
     subject
  end
end

这种用途可以起作用，但突然之间却没有。我确实将表的名称更改为“subject”，并相应地更改了视图和控制器。它似乎正在寻找id？主题是一个字符串。有什么建议？感谢。

Answer 1

根据您的关联模型，您的家庭作业属性应如下所示：

subject_id:integer description:string date:datetime completed_at:datetime

因此，您应该在subject_id

中允许subject而不是homework_params

至于collection_select方法，它应该是这样的：

f.collection_select :subject_id, Subject.order(:subject), :id, :subject

Ruby on Rails：ActiveRecord :: AssociationTypeMismatch

1 个答案: