Question

Hi there Im a beginner to rails and what Im doing seems a common usecase to me yet, its funny it seems so hard to do in Rails and not many posts on the internet about the topic:

1. I created a new rails app. Since I had a legacy database that I wanted to include in my new rails app, I replaced the “development.sqlite3” with the legacy database “Listings.sqlite3”

2. Then I generated a model “business.rb” to match the table “Businesses” in my legacy db. Here is the code for it:

   class Business < ActiveRecord::Base
   
     establish_connection "Listings_development"
   
   end
   

3. Then I modified the “config/database.yml” file to include the following:

   Listings_development:
     adapter: sqlite3
     database: db/Listings.sqlite3
     pool: 5
     timeout: 5000
   
   Listings_test:
     adapter: sqlite3
     database: db/Listings.sqlite3
     pool: 5
     timeout: 5000
   
   Listings_production:
     adapter: sqlite3
     database: db/Listings.sqlite3
     pool: 5
     timeout: 5000
   

4. After that I generated the controller called “businesses_controller.rb” which has the following code:

   class BusinessesController < ApplicationController
     def show
   
     end
   
     def index
       @businesses = Business.all
       respond_to do |format|
         format.html #index.html.erb
       end
     end
   end
   

5. Finally I changed the “config/routes.rb” file to the following:

   Directory::Application.routes.draw do
     resources :businesses
   
   
     get "business/index"
   
     match ':controller(/:action(/:id))(.:format)'
   

6. Lastly I added a view file “index.html.erb:

   <h1>Listing businesses</h1>
   <table>
     <tr>
       <th>Name:</th>
       <th>Phone Number:</th>
       <th>Address:</th>
     </tr>
   
   <% @businesses.each do |business| %>
     <tr>
       <td><%= business.company_name %></td>
       <td><%= business.phone_number %></td>
       <td><%= business.address %></td>
   

I thought I was done, I had successfully managed to incorporate my legacy database and its data in my new rails app. But when I typed in “http://localhost:3000/businesses/” in my browser window. I get this error on the screen:

Showing /Users/AM/Documents/RailsWS/cmdLineWS/Directory/app/views/businesses/index.html.erb
where line #14 raised:

undefined method `company_name' for #<Business:0x00000104e1d0e8>
Extracted source (around line #14):

11: 
12: <% @businesses.each do |business| %>
13:   <tr>
14:     <td><%= business.company_name %></td>
15:     <td><%= business.phone_number %></td>
16:     <td><%= business.address %></td>
17:     <td><%= link_to 'Show', business %></td>
Rails.root: /Users/AM/Documents/RailsWS/cmdLineWS/Directory

Whats up with Rails?? Is it really that complex to include a legacy db? I thought the whole point of rails was rapid prototyping.

Here is a snapshot of my Listings.db file

Answer 1

The problem could be caused by the fact the businesses’ columns contains spaces and uppercase chars (e.g. I see “Company Name” in the screenshot instead of the wanted “company_name”). I don’t know if rails support this kind of attribute names.

BTW is not a good practice have spaces and other strange characters in column names (in my humble opinion)