Adding a custom data source to a standard entity


I want to add fields in a standard entity which are mapped to a custom table. I am not sure if I should extend the entity or create a new one. Also when I am trying to extend the entity I am unable to add a new data source. However it seems I can add a data source inside the data source which is already present. Not sure if this is the best approach could anyone help me out here please?

Currently I am adding my custom data source Table1 inside the data source which is already present as showed in screen shot. Any help would be much appreciated.

Thanks & Regards

Whether you should create a brand-new entity or modify an existing one depends on what you want to achieve. Either you want to change the existing entity, or you want a new entity with custom behavior, while keeping the existing entity as it is. Or you need such changes that aren’t really possible (and/or meaningful) with extensions. For example, you want a different entity key.

Adding an extra top-level datasource wouldn’t make sense anyway, would it?