How do I clear tracked entities in entity framework

Question

I am running some correction code that runs over a big pile of entities, as it progress its speed decreases, that is because the number of tracked entities in the context increase with each iteration, It can take long so I am saving changes at the end of each iteration. Each iteration is independent and does not change the previosuly loaded entities.

I know I can turn off change tracking but I do not want to, because it is not a bulk insert code, but loading the entities and calculating a few things and if the numbers are not correct set the new numbers and update/delete/create some additional entities. I know I can create a new DbContext for each iteration and probably that would run faster than doing all in the same instance, but I am thinking that there might be a better way.

So the question is; Is there a way of clearing the entities previously loaded in the db context?

Answer 1

You can add a method to your DbContext or an extension method that uses the ChangeTracker to detach all the Added, Modified, and Deleted entities:

public void DetachAllEntities() {     var changedEntriesCopy = this.ChangeTracker.Entries()         .Where(e => e.State == EntityState.Added ||                     e.State == EntityState.Modified ||                     e.State == EntityState.Deleted)         .ToList();      foreach (var entry in changedEntriesCopy)         entry.State = EntityState.Detached; }