外键约束，博客帖子，acts_as_votable

Question

所以我安装了gem acts_as_votable或者它所调用的任何东西。伟大的小投票系统。但是在我的管理员中，当我去删除博客文章时，我得到一个带有sqlite的外键约束失败错误消息。我知道它与db表有关，如果你试图删除一个在另一个表上有外键的表上的记录，除非on_delete ::为外键定义了cascade等，否则会导致问题。我是不知道我怎么能为acts_as_votable gem做这个。谁知道？谢谢！

博客模型：

class HomeBlog < ApplicationRecord
  mount_uploader :image, ImageUploader
  has_many :hashtaggings
  has_many :hashtags, through: :hashtaggings

  acts_as_votable

  def all_hashes=(names)
    self.hashtags = names.split(",").map do |name|
      Hashtag.where(name: name.strip).first_or_create!
    end
  end

  def all_hashes
    self.hashtags.map(&:name).join(", ")
  end
end

博客控制器：

class Admin::HomeBlogsController < Admin::AdminController

  before_action :set_home_blog, only: [:show, :destroy]


  def destroy
    @admin_home_blog.destroy!
    respond_to do |format|
      format.html { redirect_to admin_home_blogs_path, notice: 'Blog post was successfully deleted.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_home_blog
      @admin_home_blog = Admin::HomeBlog.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def admin_home_blog_params
      params.require(:home_blog).permit(:name, :entry, :image, :all_hashes)
    end
  end

页面视图：

<h3 id="blog-index-title">Blog Posts</h3>


<span class="pagination"><%= will_paginate @admin_home_blogs %></span>
<% @admin_home_blogs.each do |h| %>

<div id="admin-blog-index">
  <%= link_to h.name, h %> | <button type="button"><%= link_to "delete", admin_home_blog_path(h), :style=>'color:white', method: :delete, data: {confirm: "Are you sure?"}%></button>
</div><br />
<% end %>

错误信息：

SQLite3 :: ConstraintException：FOREIGN KEY约束失败：DELETE FROM“home_blogs”WHERE“home_blogs”。“id”=？

Answer 1

我相信这个问题是你需要在删除帖子时销毁依赖帖子的记录。

... 

has_many :hashtaggings, dependent: :destroy
has_many :hashtags, through: :hashtaggings, dependent: :destroy

...