Question

I have two entities: Client, and AccountPlan, that have a 1 to 0..1 relationship. I would like to fetch my Clients, ordered first by Clients that have an AccountPlan, and then by Clients that do not. When I try the following Linq to Nhibernate query:

        return NHibernateSession.Current.Query<Client>()
            .Where(x => x.SalesRepId == id)
            .OrderBy(x => x.AccountPlan == null);

I get a QuerySyntaxException with the following message:

{“Exception of type ‘Antlr.Runtime.NoViableAltException’ was thrown.
[.OrderBy(.Where(NHibernate.Linq.NhQueryable`1[FIS.AccountManagement.Core.Domain.Client],
Quote((x, ) => (Equal(x.SalesRepId, p1))), ), Quote((x, ) =>
(Equal(x.AccountPlan, ))), )]”}

Here’s the mapping relationship between the two entities, if that’s important:

    public ClientMap()
    {
        HasOne(x => x.AccountPlan).PropertyRef(r => r.Client);
    }


    public AccountPlanMap()
    {
        DynamicInsert();

        References(x => x.Client, "EntityID");
    }

Does anyone know of a query from one of NHibernate’s myriad APIs that will accomplish what I want? Thanks in advance.

Answer 1

two queries in one roundtrip concated together

var clientsWithPlan = NHibernateSession.Current.Query<Client>()
    .Where(x => x.SalesRepId == id)
    .Where(x => x.AccountPlan != null)
    .Future();

var clientsWithoutPlan = NHibernateSession.Current.Query<Client>()
    .Where(x => x.SalesRepId == id)
    .Where(x => x.AccountPlan == null)
    .Future();

return clientsWithPlan.Concat(clientsWithoutPlan);