Fix learning_materials schema mismatch in production

app/models/learning_material.rb

@@ -20,18 +20,12 @@
 #  index_learning_materials_on_title     (title)
 #
 class LearningMaterial < ApplicationRecord
-  # Map app-level attribute names to the current DB column names
-  # DB columns (per schema.rb): thumbnail, link
-  # App code expects: thumbnail_url, link_url
-  alias_attribute :thumbnail_url, :thumbnail
-  alias_attribute :link_url, :link
-
   enum :level, { beginner: 0, intermediate: 1, expert: 2 }
 
   validates :title, presence: true
   validates :level, presence: true
-  validates :link_url, presence: true, format: URI::DEFAULT_PARSER.make_regexp(%w[http https])
-  validates :thumbnail_url, allow_blank: true, format: URI::DEFAULT_PARSER.make_regexp(%w[http https])
+  validates :link, presence: true, format: URI::DEFAULT_PARSER.make_regexp(%w[http https])
+  validates :thumbnail, allow_blank: true, format: URI::DEFAULT_PARSER.make_regexp(%w[http https])
 
   scope :featured, -> { where(featured: true) }
   scope :by_level, ->(lvl) { lvl.present? ? where(level: levels[lvl]) : all }

app/views/learning_materials/index.html.erb

@@ -27,16 +27,16 @@
       <div class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-2 gap-4">
         <% @featured_materials.each do |m| %>
           <div class="card bg-base-100 shadow-md overflow-hidden w-full transition-transform duration-300 hover:-translate-y-1 hover:shadow-xl">
-            <% if m.thumbnail_url.present? %>
+            <% if m.thumbnail.present? %>
               <figure class="w-full aspect-[4/3] max-h-40 overflow-hidden">
-                <img src="<%= m.thumbnail_url %>" alt="<%= m.title %> thumbnail" class="w-full h-full object-cover transition-transform duration-300 ease-out hover:scale-105">
+                <img src="<%= m.thumbnail %>" alt="<%= m.title %> thumbnail" class="w-full h-full object-cover transition-transform duration-300 ease-out hover:scale-105">
               </figure>
             <% end %>
             <div class="card-body p-2">
               <span class="badge badge-secondary capitalize w-fit text-[10px]"><%= m.level %></span>
               <h3 class="card-title text-lg text-black mt-1"><%= m.title %></h3>
               <div class="card-actions justify-start mt-2">
-                <%= link_to 'Open resource', m.link_url, class: 'link link-primary text-sm transition-colors duration-200 hover:underline', target: '_blank', rel: 'noopener' %>
+                <%= link_to 'Open resource', m.link, class: 'link link-primary text-sm transition-colors duration-200 hover:underline', target: '_blank', rel: 'noopener' %>
               </div>
             </div>
           </div>
@@ -50,16 +50,16 @@
       <% @materials.each_with_index do |m, i| %>
         <div class="pb-6 border-b border-dotted border-gray-300 w-full max-w-md"> <!-- from sm → md -->
           <div class="card bg-base-100 shadow-md overflow-hidden w-full max-w-md transition-transform duration-300 hover:-translate-y-1 hover:shadow-xl"> <!-- slightly larger card -->
-            <% if m.thumbnail_url.present? %>
+            <% if m.thumbnail.present? %>
               <figure class="w-full aspect-video max-h-48 overflow-hidden"> <!-- a little taller thumbnail -->
-                <img src="<%= m.thumbnail_url %>" alt="<%= m.title %> thumbnail" class="w-full h-full object-cover transition-transform duration-300 ease-out hover:scale-105">
+                <img src="<%= m.thumbnail %>" alt="<%= m.title %> thumbnail" class="w-full h-full object-cover transition-transform duration-300 ease-out hover:scale-105">
               </figure>
             <% end %>
             <div class="card-body p-3 md:p-4"> <!-- slightly more breathing room -->
               <span class="badge badge-ghost capitalize w-fit text-xs md:text-sm"><%= m.level %></span>
               <h3 class="card-title text-base mt-1"><%= m.title %></h3>
               <div class="card-actions justify-start mt-2">
-                <%= link_to 'Open resource', m.link_url, class: 'link link-primary text-sm transition-colors duration-200 hover:underline', target: '_blank', rel: 'noopener' %>
+                <%= link_to 'Open resource', m.link, class: 'link link-primary text-sm transition-colors duration-200 hover:underline', target: '_blank', rel: 'noopener' %>
               </div>
             </div>
           </div>

config/motor.yml

@@ -19,8 +19,8 @@ resources:
     columns:
     - name: title
     - name: level
-    - name: link_url
-    - name: thumbnail_url
+    - name: link
+    - name: thumbnail
     - name: featured
   updated_at: 2025-09-10 22:08:00.000000000 +00:00
 configs:

db/migrate/20250907005500_create_learning_materials.rb

@@ -9,8 +9,8 @@ def change
     create_table :learning_materials do |t|
       t.string :title, null: false
       t.integer :level, null: false, default: 0
-      t.string :thumbnail_url
-      t.string :link_url, null: false
+      t.string :thumbnail
+      t.string :link, null: false
       t.boolean :featured, null: false, default: false
       t.text :description
 

db/migrate/20250912215406_rename_learning_materials_url_columns.rb

@@ -0,0 +1,11 @@
+class RenameLearningMaterialsUrlColumns < ActiveRecord::Migration[7.2]
+  def change
+    if column_exists?(:learning_materials, :link_url)
+      rename_column :learning_materials, :link_url, :link
+    end
+
+    if column_exists?(:learning_materials, :thumbnail_url)
+      rename_column :learning_materials, :thumbnail_url, :thumbnail
+    end
+  end
+end

db/seeds.rb

@@ -7,16 +7,16 @@
 if defined?(LearningMaterial)
   LearningMaterial.find_or_create_by!(title: 'Rails Guides') do |lm|
     lm.level = :beginner
-    lm.thumbnail_url = 'https://rubyonrails.org/images/rails-logo.svg'
-    lm.link_url = 'https://guides.rubyonrails.org/'
+    lm.thumbnail = 'https://rubyonrails.org/images/rails-logo.svg'
+    lm.link = 'https://guides.rubyonrails.org/'
     lm.featured = true
     lm.description = 'Official Rails Guides for beginners to experts.'
   end
 
   LearningMaterial.find_or_create_by!(title: 'Ruby Official') do |lm|
     lm.level = :intermediate
-    lm.thumbnail_url = 'https://www.ruby-lang.org/images/header-ruby-logo.png'
-    lm.link_url = 'https://www.ruby-lang.org/en/documentation/'
+    lm.thumbnail = 'https://www.ruby-lang.org/images/header-ruby-logo.png'
+    lm.link = 'https://www.ruby-lang.org/en/documentation/'
     lm.featured = false
     lm.description = 'Official Ruby documentation and resources.'
   end

test/controllers/learning_materials_controller_test.rb

@@ -44,7 +44,7 @@ class LearningMaterialsControllerTest < ActionDispatch::IntegrationTest
   #     LearningMaterial.create!(
   #       title: "Material #{i}",
   #       level: :beginner,
-  #       link_url: "https://example.com/#{i}"
+  #       link: "https://example.com/#{i}"
   #     )
   #   end
   #

test/models/learning_material_test.rb

@@ -35,8 +35,7 @@ class LearningMaterialTest < ActiveSupport::TestCase
     assert_not lm.valid?
     assert_includes lm.errors.attribute_names, :title
     assert_includes lm.errors.attribute_names, :level
-    # model uses alias_attribute :link_url, :link
-    assert_includes lm.errors.attribute_names, :link_url
+    assert_includes lm.errors.attribute_names, :link
   end
 
   test 'enum levels' do

test/system/learning_materials_test.rb

@@ -4,10 +4,10 @@
 
 class LearningMaterialsTest < ApplicationSystemTestCase
   test 'view learning materials index with search and filter' do
-    LearningMaterial.create!(title: 'Ruby Basics', level: :beginner, link_url: 'https://ruby-lang.org',
-                             thumbnail_url: 'https://example.com/a.png')
-    LearningMaterial.create!(title: 'Rails Advanced', level: :expert, link_url: 'https://rubyonrails.org',
-                             thumbnail_url: 'https://example.com/b.png', featured: true)
+    LearningMaterial.create!(title: 'Ruby Basics', level: :beginner, link: 'https://ruby-lang.org',
+                             thumbnail: 'https://example.com/a.png')
+    LearningMaterial.create!(title: 'Rails Advanced', level: :expert, link: 'https://rubyonrails.org',
+                             thumbnail: 'https://example.com/b.png', featured: true)
 
     visit learning_materials_path