#55

backend/db/migrate/20260919030000_add_columns_to_tag_names.rb

@@ -1,9 +1,12 @@
 class AddColumnsToTagNames < ActiveRecord::Migration[8.0]
   def up
+    add_reference :tag_names, :tag, after: :id, foreign_key: true
     add_column :tag_names, :language_code, :string,
-               limit: 16, null: false, after: :id, default: 'ja'
+               limit: 16, null: false, after: :tag_id, default: 'ja'
     add_column :tag_names, :script_code, 'CHAR(4)',
                null: false, after: :name, default: 'Jpan'
+    add_column :tag_names, :primary_flg, :boolean,
+               null: false, after: :script_code, default: true
 
     add_foreign_key :tag_names, :languages, column: :language_code, primary_key: :code
     add_foreign_key :tag_names, :scripts, column: :script_code, primary_key: :code
@@ -13,16 +16,44 @@ class AddColumnsToTagNames < ActiveRecord::Migration[8.0]
 
     change_column_default :tag_names, :language_code, from: 'ja', to: nil
     change_column_default :tag_names, :script_code, from: 'Jpan', to: nil
+
+    execute <<~SQL
+      UPDATE
+        tag_names tn
+        LEFT JOIN
+          tags AS t
+          ON
+            t.tag_name_id = COALESCE(tn.canonical_id, tn.id)
+      SET
+        tn.tag_id = t.id
+      , tn.primary_flg = CASE
+                         WHEN tn.canonical_id IS NULL THEN
+                           1
+                         ELSE
+                           0
+                         END
+    SQL
+
+    change_column_default :tag_names, :primary_flg, from: true, to: nil
+
+    add_column :tag_names, :primary_tag_id, :bigint,
+               as: 'CASE WHEN primary_flg THEN tag_id ELSE NULL END'
+    add_index :tag_names, [:primary_tag_id, :language_code], unique: true
   end
 
   def down
+    remove_index :tag_names, [:primary_tag_id, :language_code]
+    remove_column :tag_names, :primary_tag_id
+
     remove_foreign_key :tag_names, column: :language_code
     remove_foreign_key :tag_names, column: :script_code
 
     remove_index :tag_names, [:language_code, :name]
     add_index :tag_names, :name, unique: true
 
+    remove_column :tag_names, :primary_flg
     remove_column :tag_names, :script_code
     remove_column :tag_names, :language_code
+    remove_reference :tag_names, :tag, foreign_key: true
   end
 end