1 files changed, 31 insertions, 0 deletions
diff --git a/db/migrate/20210906100021_delete_project_namespace_trigger.rb b/db/migrate/20210906100021_delete_project_namespace_trigger.rb
new file mode 100644
index 00000000000..ce68cf7d6d4
--- /dev/null
+++ b/db/migrate/20210906100021_delete_project_namespace_trigger.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class DeleteProjectNamespaceTrigger < Gitlab::Database::Migration[1.0]
+  include Gitlab::Database::SchemaHelpers
+
+  TRIGGER_NAME = "trigger_delete_project_namespace_on_project_delete"
+  FUNCTION_NAME = 'delete_associated_project_namespace'
+
+  def up
+    create_trigger_function(FUNCTION_NAME, replace: true) do
+      <<~SQL
+        DELETE FROM namespaces
+        WHERE namespaces.id = OLD.project_namespace_id AND
+        namespaces.type = 'Project';
+        RETURN NULL;
+      SQL
+    end
+
+    execute(<<~SQL.squish)
+      CREATE TRIGGER #{TRIGGER_NAME}
+        AFTER DELETE ON projects FOR EACH ROW
+        WHEN (OLD.project_namespace_id IS NOT NULL)
+        EXECUTE FUNCTION #{FUNCTION_NAME}();
+    SQL
+  end
+
+  def down
+    drop_trigger(:projects, TRIGGER_NAME)
+    drop_function(FUNCTION_NAME)
+  end
+end