---
category: [Administration & Integrations, Administration & Integrations/Custom Integrations & Apps, Platform and Product Extensions, Platform and Product Extensions/Workday Extend, Platform and Product Extensions/Integration]
keyword: [Extend, Model Components, Extend Business Objects, MCBO, Model Component Business Objects, Business Objects, Model BO]
nav: wcp_docs
parent_url: /wcp_docs/
title: >- 
  Reference: Reporting and Object Dating Restrictions
layout: subsection
---

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If you create a new business object as part of your Extend app which targets a referenceable Workday-delivered business object, you also create a single-instance and one-way object relationship between the business objects. This association introduces key restrictions when you build your Extend app.

## <a id="section_wxw_42d_s4b"></a>Assign Primary Report Data Source

When you create a new report, you can't traverse the object model graph from a Workday-delivered business object to a business object you created within your Extend app. You must assign the Data Source of the business object you created as the primary Report Data Source in the report and traverse to the instances of the Workday-delivered business object from this Data Source.

Example: In the Workdog sample app, where employees can register to bring their Workdogs to their workplace, you can create a new Workdog business object as part of the Extend app. The Workdog business object needs to reference the Workday-delivered Worker business object. When you create a report to view a list of all Workers who have registered their Workdog, you must assign Workdog as the primary Report Data Source. To report on Workers, you must leverage the association between Workdog and Worker.

## <a id="section_k1v_pjd_s4b"></a>Effective Dating Business Objects

Business objects created within Extend apps don't support effective dating. To report on values for a given date, you can use an object that stores a transaction log of changes to a business object with dates.

### Related Information

[Concept: Joiner Business Objects](/wcp_docs/gkd1617921717692.html)