1 files changed, 44 insertions, 0 deletions
diff --git a/db/migrate/20161031174110_migrate_subscriptions_project_id.rb b/db/migrate/20161031174110_migrate_subscriptions_project_id.rb
new file mode 100644
index 00000000000..549145a0a65
--- /dev/null
+++ b/db/migrate/20161031174110_migrate_subscriptions_project_id.rb
@@ -0,0 +1,44 @@
+class MigrateSubscriptionsProjectId < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = true
+  DOWNTIME_REASON = 'Subscriptions will not work as expected until this migration is complete.'
+
+  def up
+    execute <<-EOF.strip_heredoc
+      UPDATE subscriptions
+      SET project_id = (
+        SELECT issues.project_id
+        FROM issues
+        WHERE issues.id = subscriptions.subscribable_id
+      )
+      WHERE subscriptions.subscribable_type = 'Issue';
+    EOF
+
+    execute <<-EOF.strip_heredoc
+      UPDATE subscriptions
+      SET project_id = (
+        SELECT merge_requests.target_project_id
+        FROM merge_requests
+        WHERE merge_requests.id = subscriptions.subscribable_id
+      )
+      WHERE subscriptions.subscribable_type = 'MergeRequest';
+    EOF
+
+    execute <<-EOF.strip_heredoc
+      UPDATE subscriptions
+      SET project_id = (
+        SELECT projects.id
+        FROM labels INNER JOIN projects ON projects.id = labels.project_id
+        WHERE labels.id = subscriptions.subscribable_id
+      )
+      WHERE subscriptions.subscribable_type = 'Label';
+    EOF
+  end
+
+  def down
+    execute <<-EOF.strip_heredoc
+      UPDATE subscriptions SET project_id = NULL;
+    EOF
+  end
+end