1 files changed, 21 insertions, 0 deletions
diff --git a/db/migrate/20221111142921_add_hierarchy_restrictions.rb b/db/migrate/20221111142921_add_hierarchy_restrictions.rb
new file mode 100644
index 00000000000..dd80de04969
--- /dev/null
+++ b/db/migrate/20221111142921_add_hierarchy_restrictions.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class AddHierarchyRestrictions < Gitlab::Database::Migration[2.0]
+  UNIQUE_INDEX_NAME = 'index_work_item_hierarchy_restrictions_on_parent_and_child'
+
+  def up
+    create_table :work_item_hierarchy_restrictions do |t|
+      t.references :parent_type, index: true, null: false,
+                                 foreign_key: { on_delete: :cascade, to_table: :work_item_types }
+      t.references :child_type, index: true, null: false,
+                                foreign_key: { on_delete: :cascade, to_table: :work_item_types }
+      t.integer :maximum_depth, limit: 2
+
+      t.index [:parent_type_id, :child_type_id], unique: true, name: UNIQUE_INDEX_NAME
+    end
+  end
+
+  def down
+    drop_table :work_item_hierarchy_restrictions
+  end
+end