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c#entity-frameworkone-to-manysavechanges
Brent
Brent

Reputation: 4876

Updating one-to-many relationships without SaveChanges

When a call is made to the SaveChanges() method of an context, the relationships on the other side of the change are automatically updated.

For instance if I had a teacher mrX with a virtual ICollection of students including littleJohnny

mrX.Students.Remove(littleJohnny);
Debug.Assert(littleJohnny.Teacher!=null); //assert should pass
context.SaveChanges();
Debug.Assert(littleJohnny.Teacher==null); //assert should pass

mrX.Students.Add(littleJohnny);
context.SaveChanges();//revert to previous state

littleJohnny.Teacher=null;
Debug.Assert(mrX.Students.Contains(littleJohnny)); //assert should pass
context.SaveChanges();
Debug.Assert(!mrX.Students.Contains(littleJohnny)); //assert should pass

  1. Is there any way to update such relationships without saving the data to the database in Entity Framework 4.3 and 5.0 ?

  2. In a different scenario, If I have a ViewModel which maps to the above entities, is there a simple way I can copy this EF behavior -> that is, track the relationships and update the relationships on calling a method?

Upvotes: 0

Views: 229

Answers (1)

qujck
qujck

Reputation: 14580

try calling context.ChangeTracker.DetectChanges()

if that doesn't work then your related entities have not been initialised correctly

Upvotes: 1

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