1 files changed, 33 insertions, 0 deletions
diff --git a/db/migrate/20160603180330_remove_duplicated_notification_settings.rb b/db/migrate/20160603180330_remove_duplicated_notification_settings.rb
new file mode 100644
index 00000000000..4f4f58b1619
--- /dev/null
+++ b/db/migrate/20160603180330_remove_duplicated_notification_settings.rb
@@ -0,0 +1,33 @@
+# rubocop:disable all
+class RemoveDuplicatedNotificationSettings < ActiveRecord::Migration
+  def up
+    duplicates = exec_query(%Q{
+      SELECT user_id, source_type, source_id
+      FROM notification_settings
+      GROUP BY user_id, source_type, source_id
+      HAVING COUNT(*) > 1
+    })
+
+    duplicates.each do |row|
+      uid = row['user_id']
+      stype = connection.quote(row['source_type'])
+      sid = row['source_id']
+
+      execute(%Q{
+        DELETE FROM notification_settings
+        WHERE user_id = #{uid}
+        AND source_type = #{stype}
+        AND source_id = #{sid}
+        AND id != (
+          SELECT id FROM (
+            SELECT min(id) AS id
+            FROM notification_settings
+            WHERE user_id = #{uid}
+            AND source_type = #{stype}
+            AND source_id = #{sid}
+          ) min_ids
+        )
+      })
+    end
+  end
+end