NHibernate Linq // FirstOrDefault with children objects // Possible?

Question

I have an Employee. Employee has a single (parent) Department. 1:N, Department to Employee. Employee has N EmployeeToJobTitleMatchLink(s).
Employee has N number of ParkingArea(s).

When using NHibernate and Linq, and "FirstOrDefault"..

            EmployeeNHEntity firstOrDefaultEmp = session.Query<EmployeeNHEntity>()
                .Fetch(e => e.MyEmployeeToJobTitleMatchLinks)
                .Fetch(e => e.ParentDepartment)
                .Fetch(e => e.MyParkingAreas)
                .Where(e => e.EmployeeUUID == employeeUuid)
                .FirstOrDefault();

I get this sql. (the most important part is the "Top 1".

exec sp_executesql N'select TOP (1)  employeenh0_.EmployeeUUID as Employee1_1_0_, myemployee1_.LinkSurrogateUUID as LinkSurr1_3_1_, department2_.DepartmentUUID as Departme1_0_2_, parkingare4_.ParkingAreaUUID as ParkingA1_5_3_, employeenh0_.MyVersionColumn as MyVersio2_1_0_, employeenh0_.SSN as SSN1_0_, employeenh0_.LastName as LastName1_0_, employeenh0_.FirstName as FirstName1_0_, employeenh0_.CreateDate as CreateDate1_0_, employeenh0_.HireDate as HireDate1_0_, employeenh0_.ParentDepartmentUUID as ParentDe8_1_0_, myemployee1_.PriorityRank as Priority2_3_1_, myemployee1_.JobStartedOnDate as JobStart3_3_1_, myemployee1_.TheEmployeeUUID as TheEmplo4_3_1_, myemployee1_.TheJobTitleUUID as TheJobTi5_3_1_, myemployee1_.TheEmployeeUUID as TheEmplo4_0__, myemployee1_.LinkSurrogateUUID as LinkSurr1_0__, department2_.MyVersionColumn as MyVersio2_0_2_, department2_.DepartmentName as Departme3_0_2_, department2_.CreateDate as CreateDate0_2_, parkingare4_.ParkingAreaName as ParkingA2_5_3_, parkingare4_.CreateDate as CreateDate5_3_, myparkinga3_.AbcEmployeeUUID as AbcEmplo1_1__, myparkinga3_.AbcParkingAreaUUID as AbcParki2_1__ from dbo.Employee employeenh0_ left outer join dbo.EmployeeToJobTitleMatchLink myemployee1_ on employeenh0_.EmployeeUUID=myemployee1_.TheEmployeeUUID left outer join dbo.Department department2_ on employeenh0_.ParentDepartmentUUID=department2_.DepartmentUUID left outer join EmployeeToParkingAreaLink myparkinga3_ on employeenh0_.EmployeeUUID=myparkinga3_.AbcEmployeeUUID left outer join dbo.ParkingArea parkingare4_ on myparkinga3_.AbcParkingAreaUUID=parkingare4_.ParkingAreaUUID where employeenh0_.EmployeeUUID=@p0',N'@p0 uniqueidentifier',@p0='64409648-15C5-4B67-BCE2-A265012E0926'

The issue is that I get 1 row (top 1). While I have 1 Employee, I (should) have many rows in the resultset.

Now, if I use the below, I get the desired result. (A single employee with the children objects populated)....if there is a match on the surrogate-key (EmployeeUUID), there is one item in the collection.

            IList<EmployeeNHEntity> emps = session.Query<EmployeeNHEntity>()
                .Fetch(e => e.MyEmployeeToJobTitleMatchLinks)
                .Fetch(e => e.ParentDepartment)
                .Fetch(e => e.MyParkingAreas)
                .Where(e => e.EmployeeUUID == employeeUuid)
                .ToList();

            EmployeeNHEntity emp = null;
            if(null!=emps)
            {
                if (emps.Count > 0)
                {
                    emp = emps[0];
                }
            }

which generates this sql

exec sp_executesql N'select employeenh0_.EmployeeUUID as Employee1_1_0_, myemployee1_.LinkSurrogateUUID as LinkSurr1_3_1_, department2_.DepartmentUUID as Departme1_0_2_, parkingare4_.ParkingAreaUUID as ParkingA1_5_3_, employeenh0_.MyVersionColumn as MyVersio2_1_0_, employeenh0_.SSN as SSN1_0_, employeenh0_.LastName as LastName1_0_, employeenh0_.FirstName as FirstName1_0_, employeenh0_.CreateDate as CreateDate1_0_, employeenh0_.HireDate as HireDate1_0_, employeenh0_.ParentDepartmentUUID as ParentDe8_1_0_, myemployee1_.PriorityRank as Priority2_3_1_, myemployee1_.JobStartedOnDate as JobStart3_3_1_, myemployee1_.TheEmployeeUUID as TheEmplo4_3_1_, myemployee1_.TheJobTitleUUID as TheJobTi5_3_1_, myemployee1_.TheEmployeeUUID as TheEmplo4_0__, myemployee1_.LinkSurrogateUUID as LinkSurr1_0__, department2_.MyVersionColumn as MyVersio2_0_2_, department2_.DepartmentName as Departme3_0_2_, department2_.CreateDate as CreateDate0_2_, parkingare4_.ParkingAreaName as ParkingA2_5_3_, parkingare4_.CreateDate as CreateDate5_3_, myparkinga3_.AbcEmployeeUUID as AbcEmplo1_1__, myparkinga3_.AbcParkingAreaUUID as AbcParki2_1__ from dbo.Employee employeenh0_ left outer join dbo.EmployeeToJobTitleMatchLink myemployee1_ on employeenh0_.EmployeeUUID=myemployee1_.TheEmployeeUUID left outer join dbo.Department department2_ on employeenh0_.ParentDepartmentUUID=department2_.DepartmentUUID left outer join EmployeeToParkingAreaLink myparkinga3_ on employeenh0_.EmployeeUUID=myparkinga3_.AbcEmployeeUUID left outer join dbo.ParkingArea parkingare4_ on myparkinga3_.AbcParkingAreaUUID=parkingare4_.ParkingAreaUUID where employeenh0_.EmployeeUUID=@p0',N'@p0 uniqueidentifier',@p0='64409648-15C5-4B67-BCE2-A265012E0926'

The [0] indexer trick is ok. But just isn't as clean as I'd like my Linq code to be.

Any suggestions now LINQ syntax to get Top 1 Employee, but with all the children objects?

Answer 1

EmployeeNHEntity firstOrDefaultEmp = session.Query<EmployeeNHEntity>()
    .Fetch(e => e.MyEmployeeToJobTitleMatchLinks)
    .Fetch(e => e.ParentDepartment)
    .Fetch(e => e.MyParkingAreas)
    .Where(e => e.EmployeeUUID == employeeUuid)
    .AsEnumerable()    <-- note this line
    .FirstOrDefault();