(Ruby on Rails6) Display of the database that got the id of the database
Machine specs
-Version 10.15.3 ・ Ruby ruby 2.6.3p62 ・ Rails 6.0.3.2
Preface
The above recorded how to display the database in the view. However, if you want to make a work with Ruby on Rails, you want to get id </ strong>! Here, the database display by id is recorded as an oblivion record. I hope it helps you with something.
Display of the database that got the id of the database
Please note that you will need to create a database for future work. For more information → To the above
Set id routes
Image of routes If you "post / register" like ↓, you want to create "My Page / Details Page" according to the number of ids. 1 to 4 are ids.
config/routes
Rails.application.routes.draw do
get 'Controller name/index'
get 'Controller name/1' => 'Controller name#Action name'
get 'Controller name/2' => 'Controller name#Action name'
get 'Controller name/3' => 'Controller name#Action name'
get 'Controller name/4' => 'Controller name#Action name'
end
If it is left as it is, routes will be described in a large number, so describe it as ↓.
config/routes
Rails.application.routes.draw do
get 'Controller name/:id' => 'Controller name#Action name'
end
↓ Example
config/routes
Rails.application.routes.draw do
get 'posts/:id' => 'posts#index'
end
I replaced the parts 1 to 4 with : id </ strong>.
Attention in routes!
If it looks like ↓ on routes, an error will occur.
(error)
config/routes
Rails.application.routes.draw do
get 'Controller name/:id' => 'Controller name#Action name'← Described first
get "/" => "forms#index"
end
If you write the : id </ strong> route of get'posts /: id'='posts # index'</ strong> before the normal route, an error will occur. So, write as ↓.
(success)
config/routes
Rails.application.routes.draw do
get "/" => "forms#index"
get 'Controller name/:id' => 'Controller name#Action name'← Described later
end
↓ Example
config/routes
Rails.application.routes.draw do
get "/" => "forms#index"
get 'posts/:id' => 'posts#index'← Described later
end
Description to controller
The controller is fine with the initial settings at this point.
app/controllers/Any_controller
class PostsController < ApplicationController
def action name
end
end
Example ↓
app/controllers/Any_controller
class PostsController < ApplicationController
def index
end
end
Get id from URL
To get the id, use params [: id] </ strong> for the controller action. params </ strong> is the method that receives the value.
app/controllers/Any_controller
class PostsController < ApplicationController
def action name
@id = params[:id]
end
end
Don't forget to use @id as controller must have @.
Example ↓
app/controllers/Any_controller
class PostsController < ApplicationController
def index
@id = params[:id]
end
end
Display in View
erb:app/views/Any/index.html.erb
<h1>Title</h1>
<p>smple text</p>
<%= "id is "#{@id}Is the screen" %>
Let's check with a browser once here
command
rails s
(URL) http://localhost:3000/posts/1
It was displayed. The content of the characters is different between the image and Qiita, but don't worry.
erb:app/views/Any/index.html.erb
<%= "id is "#{@id}Is the screen" %>
The id is read in # {@id} </ strong> of Also, since it is <% = ~~%> </ strong>, it is displayed in the view.
So far, we have set the URL and id. From here, let's get the data corresponding to the id.
Get data corresponding to id
Settings to controller
To output id equal </ strong>
Use find_by and params [: id] </ strong>.
app/controllers/Any_controller
class PostsController < ApplicationController
def action name
@table name=Database name.find_by(id: params[:id])
end
end
↓ Example
app/controllers/Any_controller
class PostsController < ApplicationController
def index
@post = Post.find_by(id: params[:id])
end
end
Glossary
find_by </ strong> is getting a value whose id column value is equal to "params [: id]". Also params [: id] </ strong> will be able to hold objects that hold the data sent from the browser to the Rails application.
Settings for views
Finally, set the views. Here, let's display the posted content and posted time.
erb:app/views/Any/index.html.erb
<h1>Title</h1>
<p>sample text</p>
<%= @post.content %>
<%= @post.created_at %>
Less than Please enter and check with your browser.
command
rails s
I typed test1 in the rails console command, and it's reflected.
Element description
erb:app/views/Any/index.html.erb
<%= @post.content %>
→content(Post text)Get
<%= @post.created_at %>
→ Get posting time
Bonus / link
If you want to link to this post, please write the following in views.
erb:app/views/Any/index.html.erb
<%= link_to(Post.content, "/Page name/#{post.id}") %>
Example ↓
erb:app/views/Any/index.html.erb
<%= link_to(post.content, "/posts/#{post.id}") %>
The above code is available on Github. If you are interested, please download it. → Github
Afterword
The above is the display of the database for which the id of the database was acquired. I am very grateful to be able to get the id and output the URL and database contents. If you devise it, you can use it in many situations. Thank you for reading.
Reference link
Books: <a href="https://www.amazon.co.jp/%E3%81%9F%E3%81%AE%E3%81%97%E3%81%84Ruby-%E7%AC%AC6 % E7% 89% 88-Informatics-IDEA-% E9% AB% 98% E6% A9% 8B / dp / 4797399848 / ref = sr_1_1? __mk_ja_JP =% E3% 82% AB% E3% 82% BF% E3% 82 % AB% E3% 83% 8A & dchild = 1 & keywords =% E3% 81% 9F% E3% 81% AE% E3% 81% 97% E3% 81% 84Ruby +% E7% AC% AC6% E7% 89% 88 & qid = 1600088731 & s = books & sr = 1-1 "target =" blank "> Fun Ruby 6th Edition
My link
Also, there is a link to the Twitter portfolio, so if you are interested, Please connect. I would be very happy to have friends who can share programming learning.
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