I have built a custom search connector to crawl and index external content types. That works quite well. I find the index entities in the search center as well through using the API of SearchServiceApplicationProxy.
But now I want to know, what is the easiest way to narrow the result of a KeywordQuery to just get results from an certain Entity-Type (e.g just the "Products" of the external system, not the "Customers"). That means I want to query by the Name and Namespace of the Entity (in conjunction with an some other search terms).
Do I have to create a managed property myself based on some crawled property? Or is there a way to fill for example the "ContentType" or "ContentClass" property from the BCS-connector? Thank you in advance.