EF CTP5 failed to update optional navigation property

Question

I have a lot of one association between "Project" and "Template".

The project has a property of type "Template".

The association is not bidirectional (the "Template" does not know the "Project").

My entity mapping for the association in the "Project":

this.HasOptional(p => p.Template);

If I create a "Project" without specifying a template, then zero is correctly inserted in the "TemplateId" column of the "Projects" table.

If I specify a template, the template identifier will be inserted correctly. Generated SQL:

update [Projects]
set    [Description] = '' /* @0 */,
       [UpdatedOn] = '2011-01-16T14:30:58.00' /* @1 */,
       [ProjectTemplateId] = '5d2df249-7ac7-46f4-8e11-ad085c127e10' /* @2 */
where  (([Id] = '8c1b2d30-b83e-4229-b0c3-fed2e36bf396' /* @3 */)
        and [ProjectTemplateId] is null)

However, if I try to change the template or even set it to null, templateId is not updated. Generated SQL:

update [Projects]
set    [UpdatedOn] = '2011-01-16T14:32:14.00' /* @0 */
where  ([Id] = '8c1b2d30-b83e-4229-b0c3-fed2e36bf396' /* @1 */)

As you can see, TemplateId is not updated.

. "Template" "Project" null , , , , !

,

[]

, , IDbSet DbContext. , , . :

public class PortfolioContext : DbContext, IDbContext
{
    public PortfolioContext(string connectionStringName) : base(connectionStringName) { }

    public IDbSet<Foo> Foos { get; set; }
    public IDbSet<Bar> Bars { get; set; }

    protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder) {

        modelBuilder.Configurations.Add(new FooMap());
        modelBuilder.Configurations.Add(new BarMap());

        base.OnModelCreating(modelBuilder);
    }

    public new IDbSet<TEntity> Set<TEntity>() where TEntity : class {
        return base.Set<TEntity>();
    }
}

public class Foo {
    public Guid Id { get; set; }
    public string Name { get; set; }
    public virtual Bar Bar { get; set; }

    public Foo()
    {
        this.Id = Guid.NewGuid();
    }
}

public class Bar
{
    public Guid Id { get; set; }
    public string Name { get; set; }

    public Bar()
    {
        this.Id = Guid.NewGuid();
    }
}

public class FooMap : EntityTypeConfiguration<Foo>
{
    public FooMap()
    {
        this.ToTable("Foos");
        this.HasKey(f => f.Id);
        this.HasOptional(f => f.Bar);
    }
}

public class BarMap : EntityTypeConfiguration<Bar>
{
    public BarMap()
    {
        this.ToTable("Bars");
        this.HasKey(b => b.Id);
    }
}

:

[Test]  
public void Template_Test()
{
    var ctx = new PortfolioContext("Portfolio");

    var foo = new Foo { Name = "Foo" };
    var bar = new Bar { Name = "Bar" };

    foo.Bar = bar;

    ctx.Set<Foo>().Add(foo);

    ctx.SaveChanges();

    object fooId = foo.Id;
    object barId = bar.Id;

    ctx.Dispose();

    var ctx2 = new PortfolioContext("Portfolio");
    var dbFoo = ctx2.Set<Foo>().Find(fooId);

    dbFoo.Bar = null; // does not update

    ctx2.SaveChanges();
}

, SQL CE 4.

Answer 1

, , - . , , , ObjectStateManager, EF SaveChanges().

using (var context = new Context())
{                
    var dbFoo = context.Foos.Find(fooId);             
    ((IObjectContextAdapter)context).ObjectContext.LoadProperty(dbFoo, f => f.Bar);

    dbFoo.Bar = null;
    context.SaveChanges();
}

:

exec sp_executesql N'update [dbo].[Foos]
set [BarId] = null
where (([Id] = @0) and ([BarId] = @1))
',N'@0 uniqueidentifier,@1 uniqueidentifier',@0='A0B9E718-DA54-4DB0-80DA-C7C004189EF8',@1='28525F74-5108-447F-8881-EB67CCA1E97F'

Answer 2

EF CTP5 ( : p), , .

1) . ProjectTemplate:

public virtual ICollection<Project> Projects {get;set;}

, "Template" null, - , :

    var project = repo.GetById(id);
var template = project.Template;
template.Projects.Remove(project);
// save changes

2) ( , ) . Project :

    public Guid? TemplateId { get; set; }
    public virtual ProjectTemplate Template { get; set; }

, .

:

this.HasOptional(p => p.Template)
.WithMany()
.HasForeignKey(p => p.TemplateId);

, null, Project ( , ):

    public virtual void RemoveTemplate() {
        this.TemplateId = null;
        this.Template = null;
    }

, , .

, .