在Ruby-on-Rails数据库中搜索字段

Question

I currently have a DB in Ruby on Rails, however, I have been having trouble with the documentation on how to do much other than list all of the items in DB. I am still new to the this language as a whole, and wish I didn't need to ask for so much help, but here it goes. My pertinent code is as follows:

migrate/(DB name)

class CreateArticles < ActiveRecord::Migration
  def change
    create_table :articles do |t|
      t.string :title
      t.text :text

      t.timestamps null: false
    end
  end
end

articles_controller.rb

class ArticlesController < ApplicationController
  def index
    @articles = Article.all

    Article.search(params[:id])
  end

  def show
    @article = Article.find(params[:search])
  end

  def new
    @article = Article.new
  end

  def edit
    @article = Article.find(params[:id])
  end

  def create
    @article = Article.new(params.require(:article).permit(:title, :text))

    if @article.save
      redirect_to @article
    else
      render 'new'
    end
  end

  def update
    @article = Article.find(params[:id])

    if @article.update(article_params)
      redirect_to @article
    else
      render 'edit'
    end
  end

  def destroy
    @article = Article.find(params[:id])
    @article.destroy

    redirect_to articles_path
  end

  private
    def article_params
      params.require(:article).permit(:title, :text)
    end
end

article.rb

class Article < ActiveRecord::Base

  validates :title, presence: true,
                    length: { minimum: 5 }

    def self.search(search)
    if search
        @article = Article.where('name LIKE ?', "%#{search}%")
    else
        @article = Article.all
    end
    end

end

index.html.rb

<h1>Listing articles</h1>

<%= link_to 'New article', new_article_path %> 

<table>
  <tr>
    <th>Title</th>
    <th>Text</th>
    <th colspan="3"></th>
  </tr>

  <% @articles.each do |article| %>
    <tr>
      <td><%= article.title %></td>
      <td><%= article.text %></td>
      <td><%= link_to 'Show', article_path(article) %></td>
      <td><%= link_to 'Edit', edit_article_path(article) %></td>
      <td><%= link_to 'Destroy', article_path(article),
              method: :delete,
              data: { confirm: 'Are you sure?' } %></td>
    </tr>
  <% end %>


  <%= form_tag articles_path, :method => 'get' do %>
     <p>
        <%= text_field_tag :search, params[:search] %>
        <%= submit_tag "Search", :name => nil %>
     </p>
 <% end %>

</table>

Thanks for any help in advance!

Answer 1

Essentially your issue is that you're trying to set controller instance variables in a class method in your model.

class ArticlesController < ApplicationController
  def index
    @articles = Article.search(params[:search])
  end 
end

article.rb

class Article < ActiveRecord::Base

  validates :title, presence: true,
                    length: { minimum: 5 }

  def self.search(search)
    if search.present?
      Article.where('title LIKE ?', "%#{search}%")
    else
      Article.all
    end
  end    
end

So now the class method does the search, returns the collection to the controller which assigns them to an instance variable for use in the view.

Answer 2

You have got your search form, made sure that is a GET one. Good. When you hit search you'll notice in your development log that there's a hit to articles#index and the browser will show the same as before. To make the search matter edit the index method in the articles controller.

def index
  @articles = Article.all.search(params[:search])
end

In Article.search you have a name where you should have a title .

PS: You've got the show method a bit wrong.