Using two Object Contexts?

Question

I created two edmx files and have to contexts.

Is there a problem with doing something like:

public DataManager
{
  protected ObjectContext _context;

  public DataManager(ObjectContext context)
  {
     _context = context;
  }
}

or is it better to have an overloaded construtor:

public DataManager
{
  protected db1entities _context;
  protected db2entities _context2;

  public DataManager(db2entities context)
  {
     _context = context;
  }

  public DataManager(db2entities context)
  {
     _context2 = context;
  }
}

I noticed if I do it the first way, then the context does not know about my entities, where as it does if I explicitly specify the context

DCNYAM · Accepted Answer · 2013-05-17 16:29:30Z

2

I'm not entirely sure what you are trying to accomplish, but you could also do this using generics (http://msdn.microsoft.com/en-us/library/512aeb7t(v=vs.110).aspx). Something like...

public class DataManager<T> where T:ObjectContext
{
  protected T _context;

  public DataManager(T context)
  {
     _context = context;
  }
}

Then ...

DataManager<db1Entities> DataManager1;
DataManager<db2Entities> DataManager2;

edited May 17, 2013 at 16:29

answered May 17, 2013 at 15:02

DCNYAM

12.2k8 gold badges57 silver badges71 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Xaisoft Over a year ago

I believe this is it. I will test it out, but basically I am just trying to pass a different context depending on what data I want to work with. Would you do me a favor and explain what T means?

bcr Over a year ago

This is a generic class. T stands for the type being used. In this case it specifies that T needs to be of type ObjectContext or classes that inherit from it.

DCNYAM Over a year ago

Like bcr said, T is sort of a placeholder for the type you specify when creating the class. The expression T:ObjectContext just limits the types you can use with this class to those of type ObjectContext of a child of that class. Basically, it just stops you from using a completely inappropriate datatype with this class.

Xaisoft Over a year ago

ok, so if I removed the Where, T Could be anything, so it is like a constraint.

DCNYAM Over a year ago

Yes. With out it, you could say DataManager<TextBox> DataManager1;. That obviously makes no sense.

Collectives™ on Stack Overflow

Using two Object Contexts?

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related