Question

I am creating graphic application and where the user can import the graphic data from a SQL Sever database. This application should be capable of handling at least 100,000+ entities. The idea to load the data faster is to load the visual data while opening the database file and non-visual data will be loaded on demand. So, the problem which I am facing is with the data loading from database using Entity Framework.

Each entity has a visual and a non-visual data associated and following is an example of one of the entity:

class Polyline
{
  Guid ID {get; set;}
  PolylineGeometry PGeometry {get; set;}
  PolylineAttribData PAttribData {get; set;}
}
class PolylineGeometry
{
  List<Point3D> PointCollection {get; set;}
}
class PolylineAttribData
{
  Image ImageData {get; set;}
}

My context class is as follows:

class GeometryData : DbContext
{
  DbSet<Polyline> Polylines {get; set;}
}

So, when we create the database context or the geometry data initially only the ID is loaded into polyline and PGeometry & PAttribData is not loaded. So, how do I load this data?

Thank You,

Pankaj

Answer 1

I think you must set Navigation Properties (refering to other entities) as virtual.

Then, wether you use lazy loading : the related entities will be loaded “on demand”, as far as your context is not disposed.

Or you can load them explicitely when needed, using Load()

You can find a good article about lazy, eager, explicit loading, pros and cons here:

http://msdn.microsoft.com/en-us/magazine/hh205756.aspx