#378

backend/db/migrate/20260621000000_add_deprecated_at_to_tags.rb

@@ -0,0 +1,20 @@
+class AddDeprecatedAtToTags < ActiveRecord::Migration[8.0]
+  def up
+    add_column :tags, :deprecated_at, :datetime, after: :category
+    add_column :tag_versions, :deprecated_at, :datetime, after: :parent_tag_ids
+
+    add_index :tags, :deprecated_at
+
+    add_check_constraint :tags, "deprecated_at IS NULL OR category <> 'nico'",
+                         name: 'chk_tags_deprecated_at_not_nico'
+  end
+
+  def down
+    remove_check_constraint :tags, name: 'chk_tags_deprecated_at_not_nico'
+
+    remove_index :tags, :deprecated_at
+
+    remove_column :tag_versions, :deprecated_at, :datetime
+    remove_column :tags, :deprecated_at
+  end
+end

backend/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -319,6 +319,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.string "event_type", null: false
     t.string "name", null: false
     t.string "category", null: false
+    t.datetime "deprecated_at"
     t.text "aliases", null: false
     t.text "parent_tag_ids", null: false
     t.datetime "created_at", null: false
@@ -336,10 +337,13 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.integer "post_count", default: 0, null: false
+    t.datetime "deprecated_at"
     t.datetime "discarded_at"
     t.integer "version_no", null: false
+    t.index ["deprecated_at"], name: "index_tags_on_deprecated_at"
     t.index ["discarded_at"], name: "index_tags_on_discarded_at"
     t.index ["tag_name_id"], name: "index_tags_on_tag_name_id", unique: true
+    t.check_constraint "(`deprecated_at` is null) or (`category` <> _utf8mb4'nico')", name: "chk_tags_deprecated_at_not_nico"
     t.check_constraint "`version_no` > 0", name: "chk_tags_version_no_positive"
   end