NHibernate. Join unrelated entities

Question

Is there any way to execute following query with native NHibernate linq provider?

var result =
    (from e1 in Session.Query()
     join e2 in Se         


        

Answer 1

I'm not quite sure when this was introduced but this is now supported by NHibernate. I am using version 3.3.1 and I have a query very similar to yours working well. The test below works for me:

[TestFixture]
public class NHibernateJoinUnrelatedEntitiesTest
{
    private ISessionFactory sessionFactory;

    [Test]
    public void I_Can_Join_Unrelated_Entities()
    {
        // Arrange
        ISession session = sessionFactory.OpenSession();

        // Act
        var results = (
                          from c in session.Query()
                          from wal in session.Query()
                          where c.Id == wal.CustomerId
                                && c.Id == 54856
                          select new { CustomerId = c.Id, Name = c.FirstName, Address = wal.IpAddress }
                      ).ToList();

        // Assert
        Assert.NotNull( results );
    }

    public class Customer
    {
        public virtual int Id { get; set; }
        public virtual string FirstName { get; set; }
    }

    public class WebsiteActivityLog
    {
        public virtual int Id { get; set; }
        public virtual int CustomerId { get; set; }
        public virtual string IpAddress { get; set; }
    }

    public class CustomerMap : ClassMap
    {
        public CustomerMap()
        {
            Id( x => x.Id );
            Map( x => x.FirstName );
        }
    }

    public class WebsiteActivityLogMap : ClassMap
    {
        public WebsiteActivityLogMap()
        {
            Id( x => x.Id );
            Map( x => x.CustomerId );
            Map( x => x.IpAddress );
        }
    }
}