is it possible to Query an Odata service and expand Child of Child entities?

Question

This sounds rather simple (and maybe I\'m missing the obvious here) but I can\'t find a solution. I know I can query an entity and return one, or many direct child entities

Answer 1

The following statement should return what you are looking for:

var query = from c in Service.Brands.Expand("Families/Models")

This will run the following odata query:

.../OData.svc/Brands?$expand=Families/Models

Here is a link to some further odata documentation:

The syntax of a $expand query option is a comma-separated list of Navigation Properties. Additionally each Navigation Property can be followed by a forward slash and another Navigation Property to enable identifying a multi-level relationship.

Answer 2

In ASP.NET OData v4, the URL convention seems to have changed. It is now:

~/Brands?$expand=Families($expand=Models)

You can also select the stuff you want in sub-entities.
For example if you want just the brand family identifiers:

~/Brands?$expand=Families($select=Id)

Furthermore, if you want only the identifiers of the brand family models, you would do that:

~/Brands?$expand=Families($expand=Models($select=Id))

...and so on. Hope this helps !