I have been trying different approaches to this problem, and this one that you can find below fits my requirements:
We have three entities: Brands, Centers and BrandsXCenters.
We cant' define the many-to-many relationship, but we can:
- Define a Validation in BrandsXCenters for Brands
- Define a Master / Detail for Centers and BrandsXCenters
With this two steps you can:
- Create the Brands.
- Create the Centers & Create the associated BrandsXCenters.
It's not a perfect solution, but controlling in the service implementation that is not possible to create a BrandsXCenters that already exists does the job.
Attached you can find the associated XML.
Hope it helps,