OData Service with multiple entity set for Create SO:

Hi Experts,

I want to create a OData service for create sales order, using BAPI_SALESORDER_CREATEFROMDAT2. For this I have created multiple entity/entity sets i.e. I need to pass Order Item, Order Partner and Partner Address as table fields to call above BAPI to Create Sales Order. Kindly suggest how to proceed further, because now I am little confused, where (In Service Implementation) I should call the BAPI, because now I have three entity sets and of course there is no association in all of them. Probably I may be wrong in approaching "Create Sales Order" OData, Please advice. However, it is clear if I create a custom structure (Consist of mandatory fields from all the three above required entities) and fill all the fields in the single entity/entity set this is achievable, but I want to use the straight BAPI and use the table structures of the BAPI directly.

Thanks & Regards

Saurabh