optional include with entity framework - entity-framework

Question

I'm working on a manager. Depending on the conditions some include must be enforced in order to get eager loading. But sometime I don't want all the data so the includes should not be applied.
This is what I've got so far.
//INFO : public partial class Entities : DbContext
var Database = new Entities();
var result = Database.Department;
if (includeHospitalEmployee) { result.Include(a => a.HospitalEmployee); }
if (includeQuickScans) { result.Include(a => a.QuickScan); }
return result;
This doesn't work. The includes aren't loaded, although the includebooleans are set to true. Query results in;
SELECT
[Extent1].[Code] AS [Code],
[Extent1].[Discipline] AS [Discipline],
[Extent1].[FinancialCode] AS [FinancialCode],
[Extent1].[Name] AS [Name],
[Extent1].[DepartmentManagerId] AS [DepartmentManagerId],
[Extent1].[Show] AS [Show],
[Extent1].[Id] AS [Id]
FROM [dbo].[Department] AS [Extent1]
But strange enough if i do this, all include are working
//INFO : public partial class Entities : DbContext
var Database = new Entities();
var result = this.businessManagersFactory.Database.Department.Include(a => a.QuickScan);;
if (includeHospitalEmployee) { result.Include(a => a.HospitalEmployee); }
if (includeQuickScans) { result.Include(a => a.QuickScan); }
return result;
see the query
SELECT
[Project1].[C1] AS [C1],
[Project1].[Code] AS [Code],
[Project1].[Discipline] AS [Discipline],
[Project1].[FinancialCode] AS [FinancialCode],
[Project1].[Name] AS [Name],
[Project1].[DepartmentManagerId] AS [DepartmentManagerId],
[Project1].[Show] AS [Show],
[Project1].[Id] AS [Id],
[Project1].[C2] AS [C2],
[Project1].[Id1] AS [Id1],
[Project1].[StartDateTime] AS [StartDateTime],
[Project1].[EndDateTime] AS [EndDateTime],
[Project1].[Shared] AS [Shared],
[Project1].[ScanStatus] AS [ScanStatus],
[Project1].[Title] AS [Title],
[Project1].[Count] AS [Count],
[Project1].[Comment] AS [Comment],
[Project1].[HospitalEmployeeId] AS [HospitalEmployeeId],
[Project1].[DepartmentId] AS [DepartmentId]
FROM ( SELECT
[Extent1].[Code] AS [Code],
[Extent1].[Discipline] AS [Discipline],
[Extent1].[FinancialCode] AS [FinancialCode],
[Extent1].[Name] AS [Name],
[Extent1].[DepartmentManagerId] AS [DepartmentManagerId],
[Extent1].[Show] AS [Show],
[Extent1].[Id] AS [Id],
1 AS [C1],
[Extent2].[Id] AS [Id1],
[Extent2].[StartDateTime] AS [StartDateTime],
[Extent2].[EndDateTime] AS [EndDateTime],
[Extent2].[Shared] AS [Shared],
[Extent2].[ScanStatus] AS [ScanStatus],
[Extent2].[Title] AS [Title],
[Extent2].[Count] AS [Count],
[Extent2].[Comment] AS [Comment],
[Extent2].[HospitalEmployeeId] AS [HospitalEmployeeId],
[Extent2].[DepartmentId] AS [DepartmentId],
CASE WHEN ([Extent2].[Id] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
FROM [dbo].[Department] AS [Extent1]
LEFT OUTER JOIN [dbo].[QuickScan] AS [Extent2] ON [Extent1].[Code] = [Extent2].[DepartmentId]
) AS [Project1]
ORDER BY [Project1].[Code] ASC, [Project1].[C2] ASC
Why is this behaviour and how to get it working properly?
regards

Answer 1

I don't have access to Visual Studio to confirm but you will probably find that assigning the return from the call to Include will sort it - it will be something like a QueryObject that implements IQueryable
var Database = new Entities();
IQueryable<Department> result = Database.Departments;
if (includeHospitalEmployee) { result = result.Include(a => a.HospitalEmployee); }
if (includeQuickScans) { result = result.Include(a => a.QuickScan); }
return result;