自引用對象和Breeze.js SaveChanges

Question

我通過在派生的EFContextProvider類中重寫BeforeSaveEntity來刪除已刪除對象的某些子項，以保留外鍵沖突：

protected override bool BeforeSaveEntity(EntityInfo entityInfo)
{
    dbEntities db = new dbEntities();
    if (entityInfo.Entity.GetType() == typeof(ServerFile) && entityInfo.EntityState == EntityState.Deleted)
    {
         ServerFile filetodelete = entityInfo.Entity as ServerFile;
         if (filetodelete.OriginalFileID == null)
         {
             IEnumerable<ServerFile> f = db.ServerFiles.Where(x => x.OriginalFileID == filetodelete.ID);
             foreach (ServerFile fd in f)
                db.ServerFiles.Remove(fd);
         }
    }
    db.SaveChanges();
}

因此，在派生為[BreezeController] ApiController類中，我刷新了上下文：

public SaveResult SaveChanges(JObject saveBundle)
{
    _contextProvider.ObjectContext.Refresh(RefreshMode.StoreWins, _contextProvider.ObjectContext.ObjectStateManager.GetObjectStateEntries(System.Data.Entity.EntityState.Deleted));
    return _contextProvider.SaveChanges(saveBundle);
}

但是我仍然得到錯誤：

An exception of type 'System.Exception' occurred in Breeze.ContextProvider.dll 
but was not handled in user code

Additional information: Store update, insert, or delete statement affected an
unexpected number of rows (0). Entities may have been modified or deleted since
entities were loaded. Refresh ObjectStateManager entries.

Answer 1

您的數據庫上沒有觸發器嗎？ 我已經看到該錯誤是過去由基礎表上的觸發器引起的。