linq - Collection Exists Criteria in WCF Data Services

Question

I'm trying to ask my OData service:

"Give me all the Products that do not have a Category"

with the Products and Category have a m2m relationship.

I've tried:

from p in Products
where p.Categories == null 
select p

and

from p in Products
where !p.Categories.Any() 
select p

and

from p in Products
where p.Categories.Count == 0
select p

but all of these give me not supported exceptions.

---

I'm not looking for alternatives or options. Please don't answer with other options.

Answer 1

My experience with WCF Data Services is that the client subset of LINQ to rest is lacking.

My biased option would be to just move it to server side where you have access to the full implementation of LINQ to entites? (or whatever you are using to implement your Data Service).

 [WebGet]
 public IQueryable<Products> GetProductsWithoutCategories(){
    /*start psudo code
      from p in Products
         where p.Categories.Count == 0
      select p


    */

 }