Question

我有4张像这样的关联表。 - 课程

class Course < ApplicationRecord
  has_many :training_frameworks, dependent: :destroy
end

- Training_framework：

class TrainingFramework < ApplicationRecord

  belongs_to :course

  has_many :training_subjects, dependent: :destroy
  has_many :subjects, through: :training_subjects

  accepts_nested_attributes_for :training_subjects
end

- Training_subject：

class TrainingSubject < ApplicationRecord
  belongs_to :subject
  belongs_to :training_framework
end

主题：

class Subject < ApplicationRecord
  has_many :training_subjects, dependent: :destroy
  has_many :training_frameworks, through: :training_subjects
end

- 在training_framework中，我想通过training_subject创建许多主题。而且我在make param中遇到麻烦并使用它当然要创建training_framwork。 - Param我在rails console中制作和测试：

param = { training_framework: { name: "version1", training_subjects_attributes: [{subject_id: 1}, {subject_id: 2}]}}
=> {:training_framework=>{:name=>"version1", :training_subject_attributes=>[{:subject_id=>1}, {:subject_id=>2}]}}

它与TrainingFramework.create(param[:traning_framework])而不是@course.training_frameworks.create(param[:traning_framework])

一起运行

我错在哪里以及如何解决？搜索与4表关联的关键是什么？

Answer 1

course与training_framework有关。您必须指定要创建course的{{1}}。

如果你使用强参数，请不要忘记允许参数training_framework（或course_id）。

course

param = {
    course_id: <course_id>, # <--
    training_framework: {
        name: "version1",
        training_subjects_attributes: [
            {subject_id: 1},
            {subject_id: 2}
        ]
    }
}

或者您可以先创建TrainingFramework.create(param[:traning_framework])，然后分配给相应的training_framework。

检查是否为适当的course创建了training_framework：course

使用has_many的嵌套属性

1 个答案: