Question

I set up the OData feed for Stack Overflow as outlined in the wonderful article Using LINQPad to Query Stack Overflow and I want to do something like:

Users.Where(x=>x.Badges.Count==0).Take(5)

to get the users that have no Badges (“Badges? We don’t need no stinkin’ badges!“). I get a DataServiceQueryException:

Answer 1

Unfortunately, OData doesn’t support aggregate functions – it supports only the limited set of querying functions described here.

Aggregate operators

All aggregate operations are unsupported against a DataServiceQuery,
including the following:

Aggregate

Average

Count

LongCount

Max

Min

Sum

Aggregate operations must either be performed on the client or be
encapsulated by a service operation.

Hopefully Microsoft will enhance the OData client in the future – it is frustrating to (seemingly) have all the power of LINQ and then not be able to use it.