Linq to sql DataContext cannot set load options after results been returned
- by David Liddle
I have two tables A and B with a one-to-many relationship respectively.
On some pages I would like to get a list of A objects only. On other pages I would like to load A with objects in B attached.
This can be handled by setting the load options
DataLoadOptions options = new DataLoadOptions();
options.LoadWith<A>(a => a.B);
dataContext.LoadOptions = options;
The trouble occurs when I first of all view all A's with load options, then go to edit a single A (do not use load options), and after edit return to the previous page.
I understand why the error is occurring but not sure how to best get round this problem. I would like the DataContext to be loaded up per request.
I thought I was achieving this by using StructureMap to load up my DataContext on a per request basis. This is all part of an n-tier application where my Controllers call Services which in turn call Repositories.
ForRequestedType<MyDataContext>()
.CacheBy(InstanceScope.PerRequest)
.TheDefault.Is.Object(new MyDataContext());
ForRequestedType<IAService>()
.TheDefault.Is.OfConcreteType<AService>();
ForRequestedType<IARepository>()
.TheDefault.Is.OfConcreteType<ARepository>();
Here is a brief outline of my Repository
public class ARepository : IARepository
{
private MyDataContext db;
public ARepository(MyDataContext context)
{
db = context;
}
public void SetLoadOptions(DataLoadOptions options)
{
db.LoadOptions = options;
}
public IQueryable<A> Get()
{
return from a in db.A
select a;
}
So my ServiceLayer, on View All, sets the load options and then gets all A's. On editing A my ServiceLayer should spin up a new DataContext and just fetch a list of A's.
When sql profiling, I can see that when I go to the Edit page it is requesting A with B objects.
