Entity Framework: SaveChanges()和AcceptAllChanges()方法
Call AcceptAllChanges() to accepts the changes on all associated entries in the ObjectStateManager so their resultant state is either unchanged or detached.
This method iterates all the ObjectStateEntry objects within the ObjectStateManager that are Added or Modified, and then sets the state of the entry to Unchanged. The Deleted items become detached.
SaveChanges() persists all updates to the data source and resets change tracking in the object context. It operates within a transaction. SaveChanges will roll back that transaction and throw an exception if any of the dirty ObjectStateEntry objects cannot be persisted.
If the SaveChanges method was called and the AcceptAllChangesAfterSave
was not specified, the user must call the AcceptAllChanges method. The
AcceptAllChanges method is useful in the scenario where a transaction
has failed and a user wants to retry.
Reference: http://msdn.microsoft.com