Joining tables from two databases using entity framework

Question

I am working on an ASP.NET MVC 4 web application. I am using Entity Framework as the data access layer, using database first approach (.edmx file).

Curr

Answer 1

@CSharper's answer is close. As @Oliver mentioned in the comments, IEnumerable loads the table into application memory, leading to crashes if you have a large database.

The solution is to use IQueryable, which can be called with LINQ - this produces SQL which is much faster.

// This is a generic method, modify to your needs
public ActionResult Details(int? id)
   var one = db.Table1.AsQueryable();
   var two = db2.Table2.AsQueryable(); 

   // since you're using MVC EF, I assume you want to put this in a viewmodel 
   // (in this case ObjectCombined)
   // assume "id" is passed as parameter 
   Object1 result1 = (from o in one where one.id == id select o).Single();
   Object2 result2 = (from t in two where t.id == o.id select t).Single();
   ObjectCombined result = new ObjectCombined(result1, result2);
   return View(result);
}