fix migrations in the future

1 files changed, 18 insertions, 0 deletions

diff --git a/db/migrate/20170707183807_add_group_id_to_milestones.rb b/db/migrate/20170707183807_add_group_id_to_milestones.rb
new file mode 100644
index 00000000000..e46fc4f80f0
--- /dev/null
+++ b/db/migrate/20170707183807_add_group_id_to_milestones.rb
@@ -0,0 +1,18 @@
+class AddGroupIdToMilestones < ActiveRecord::Migration
+  DOWNTIME = false
+
+  def up
+    change_column_null :milestones, :project_id, true
+
+    add_column :milestones, :group_id, :integer
+  end
+
+  def down
+    # We cannot rollback project_id not null constraint if there are records
+    # with null values.
+    execute "DELETE from milestones WHERE project_id IS NULL"
+
+    remove_column :milestones, :group_id
+    change_column :milestones, :project_id, :integer, null: false
+  end
+end