Question

I am very new to the entity framework, so please bear with me…

How can I relate two objects from different contexts together?

The example below throws the following exception:

System.InvalidOperationException: The relationship between the two objects cannot be defined because they are attached to different ObjectContext objects.

void MyFunction() {     using (TCPSEntities model = new TCPSEntities())     {         EmployeeRoles er = model.EmployeeRoles.First(p=>p.EmployeeId == 123);         er.Roles = GetDefaultRole();         model.SaveChanges();      } }  private static Roles GetDefaultRole() {     Roles r = null;     using (TCPSEntities model = new TCPSEntities())     {         r = model.Roles.First(p => p.RoleId == 1);     }     return r; } 

Using one context is not an option because we are using the EF in an ASP.NET application.

Answer 1

You will have to use the same context (you can pass the context to the getdefaultrole method) or rethink the relationships and extend the entity.

EDIT: Wanted to add this was for the example provided, using asp.net will require you to fully think out your context and relationship designs.

You could simply pass the context.. IE:

void MyFunction() {     using (TCPSEntities model = new TCPSEntities())     {         EmployeeRoles er = model.EmployeeRoles.First(p=>p.EmployeeId == 123);         er.Roles = GetDefaultRole(model);         model.SaveChanges();      }  }  private static Roles GetDefaultRole(TCPSEntities model) {     Roles r = null;     r = model.Roles.First(p => p.RoleId == 1);     return r; }