Rails 控制器创建 Model.new 和 Model.create 之间的动作差异 [英] Rails controller create action difference between Model.new and Model.create

问题描述

我正在学习一些 Rails 3 和 4 教程，并遇到了一些我希望得到的一些见解:

Model.new 和 Model.create 在 Create 操作方面有什么区别.我认为您确实在控制器中使用了 create 方法来进行保存，例如.@post = Post.create(params[:post]) 但看起来我错了.任何见解都非常感谢.

使用 Post.new 创建动作

def new@post = Post.new结尾定义创建@post = Post.new(post_params)@post.save重定向到 post_path(@post)结尾def post_paramsparams.require(:post).permit(:title, :body)结尾

使用 Post.create 创建动作

def new@post = Post.new结尾定义创建@post = Post.create(post_params)@post.save重定向到 post_path(@post)结尾def post_paramsparams.require(:post).permit(:title, :body)结尾

我有两个问题

• 这是否与 Rails 4 的更改有关?
• 使用 @post = Post.create(post_params) 是不好的做法吗?

解决方案

Model.new

以下实例化并初始化一个给定参数的 Post 模型:

@post = Post.new(post_params)

您必须运行 save 才能将您的实例保存在数据库中:

@post.save

模型.创建

以下实例化、初始化并在数据库中保存一个给定参数的 Post 模型:

@post = Post.create(post_params)

您不需要运行 save 命令，它已经内置了.

关于new的更多信息这里

关于create的更多信息这里

I'm going through a few Rails 3 and 4 tutorial and come across something I would love some insights on:

What is the difference between the Model.new and Model.create in regards to the Create action. I thought you do use the create method in the controller for saving eg. @post = Post.create(params[:post]) but it looks like I'm mistaken. Any insight is much appreciated.

Create action using Post.new

def new
  @post = Post.new
end

def create
  @post = Post.new(post_params)
  @post.save

  redirect_to post_path(@post)
end

def post_params
  params.require(:post).permit(:title, :body)
end

Create action using Post.create

def new
  @post = Post.new
end

def create
  @post = Post.create(post_params)
  @post.save

  redirect_to post_path(@post)
end

def post_params
  params.require(:post).permit(:title, :body)
end

I have two questions

• Is this to do with a Rails 4 change?
• Is it bad practice to use @post = Post.create(post_params)?

解决方案

Model.new

The following instantiate and initialize a Post model given the params:

@post = Post.new(post_params)

You have to run save in order to persist your instance in the database:

@post.save

Model.create

The following instantiate, initialize and save in the database a Post model given the params:

@post = Post.create(post_params)

You don't need to run the save command, it is built in already.

More informations on new here

More informations on create here

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