# posts_controller.rb
def show
@comment = @post.comments.build
end!
我通过脚手架生成了comments_controller.rb等。 然后发生了这个错误。
我不知道该怎么做。 我该如何解决这个错误?
#comments_controller.rb
class CommentsController < ApplicationController
before_action :set_comment, only: [:show, :edit, :update, :destroy]
# GET /comments
# GET /comments.json
def index
@comments = Comment.all
end
# GET /comments/1
# GET /comments/1.json
def show
end
# GET /comments/new
def new
@comment = Comment.new
end
# GET /comments/1/edit
def edit
end
# POST /comments
# POST /comments.json
def create
@comment = Comment.new(comment_params)
respond_to do |format|
if @comment.save
format.html { redirect_to @comment, notice: 'Comment was successfully created.' }
format.json { render action: 'show', status: :created, location: @comment }
else
format.html { render action: 'new' }
format.json { render json: @comment.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /comments/1
# PATCH/PUT /comments/1.json
def update
respond_to do |format|
if @comment.update(comment_params)
format.html { redirect_to @comment, notice: 'Comment was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: @comment.errors, status: :unprocessable_entity }
end
end
end
# DELETE /comments/1
# DELETE /comments/1.json
def destroy
@comment.destroy
respond_to do |format|
format.html { redirect_to comments_url }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_comment
@comment = Comment.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def comment_params
params.require(:comment).permit(:user_name, :body, :post_id)
end
end
#posts_controller.rb
# GET /posts
# GET /posts.json
def index
@posts = Post.all
end
# GET /posts/1
# GET /posts/1.json
def show
@comment = @post.comments.build
end
# GET /posts/new
def new
@post = Post.new
end
# GET /posts/1/edit
def edit
end
# POST /posts
# POST /posts.json
def create
@post = Post.new(post_params)
respond_to do |format|
if @post.save
format.html { redirect_to @post, notice: 'Post was successfully created.' }
format.json { render action: 'show', status: :created, location: @post }
else
format.html { render action: 'new' }
format.json { render json: @post.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /posts/1
# PATCH/PUT /posts/1.json
def update
respond_to do |format|
if @post.update(post_params)
format.html { redirect_to @post, notice: 'Post was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: @post.errors, status: :unprocessable_entity }
end
end
end
# DELETE /posts/1
# DELETE /posts/1.json
def destroy
@post.destroy
respond_to do |format|
format.html { redirect_to posts_url }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_post
@post = Post.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def post_params
params.require(:post).permit(:date, :subject, :body, :picture)
end
def video
end
end
答案 0 :(得分:0)
在进一步详细介绍之前。我假设您正在使用@post在帖子页面上的表单中使用它。而不是你可以使用符号
<%= form_for :comment, method: :post, url: comments_path do |f| %>
或者如果您使用嵌套路线
<%= form_for [@post, :comment], method: :post, url: comments_path do |f| %>
这将提交给控制器以供评论。
另外,请检查您的schema.rb,确保您的评论模型包含post_id
答案 1 :(得分:0)
问题在于您的comments
表格不会出现post_id
。
当
你在Rails中使用ActiveRecord associations,虽然看起来是神奇的,但它依赖于老式的关系数据库架构。其主要组成部分是primary_key
s(用于识别单个记录)和foreign_key
s(用于识别关联记录)
-
如果您希望能够将两个模型关联在一起,则需要确保拥有相应的foriegn_keys:
#app/models/post.rb
Class Post < ActiveRecord::Base
#fields id | title | body | created_at | updated_at
has_many :comments
end
#app/models/comment.rb
Class Comment < ActiveRecord::Base
#fields id | post_id | other | attributes | created_at | updated_at
belongs_to :post
end
最重要的是,您需要确保评论表中有post_id
列。如果您不这样做,则应执行迁移以插入它:
#db/migrate/new_migration.rb
Class NewMigration
def self.up
add_column :comments, :post_id, :string
end
end