LINQ to Entities Group By expression gives 'Anonymous type projection initializer should be simple name or member access expression'

Question

I am getting the above mentioned error with this expression:

var aggregate = from t in entities.TraceLines
    join m in entities.MethodNames.Where("it.Name LIKE @searchTerm", new ObjectParameter("searchTerm", searchTerm)) on t.MethodHash equals m.MethodHash
    where (t.CallTypeId & (int)types) == t.CallTypeId && t.UserSessionProcessId == m_SessionId
    group t by m.Name into d                                                   
    select new
    {
        d.Key,                                     
        d.Sum(x => x.InclusiveDurationMilliseconds) // <- squigglies on this line
    };

Any idea what is causing this error?

Answer 1

Do something like:

select new
{
    d.Key,
    Sum = d.Sum(x => x.InclusiveDurationMilliseconds)
};

It can project a property name from another property, but not from a method....