#174 エラー回避と誤記修正

2025-12-10 20:01:14 +09:00
parent 575d63dcba
commit 8b4b26065c
2 changed files with 22 additions and 2 deletions
@@ -1,7 +1,27 @@
 class AddUniqueIndexToTagImplications < ActiveRecord::Migration[8.0]
-  def change
+  def up
+    execute <<~SQL
+      DELETE
+        ti1
+      FROM
+        tag_implications ti1
+        INNER JOIN
+          tag_implications ti2
+          ON
+            ti1.tag_id = ti2.tag_id
+            AND ti1.parent_tag_id = ti2.parent_tag_id
+            AND ti1.id > ti2.id
+      ;
+    SQL
+
    add_index :tag_implications, [:tag_id, :parent_tag_id],
              unique: true,
              name: 'index_tag_implications_on_tag_id_and_parent_tag_id'
  end
+
+  def down
+    # NOTE: 重複削除は復元されなぃ．
+    remove_index :tag_implications,
+                 name: 'index_tag_implications_on_tag_id_and_parent_tag_id'
+  end
 end