[英]Entity Framework: Can't save data because of tracking
I have got a complex class.我有一个复杂的课程。 Feedback and Steps.反馈和步骤。 I am using SQL database and .Net Core 2. I can save main properties but can't save the sub class FeedbackSteps properties我正在使用 SQL 数据库和 .Net Core 2。我可以保存主要属性但无法保存子类 FeedbackSteps 属性
public class FeedbackModel
{
[Key]
public int FeedBackID { get; set; }
public DateTime FBDate { get; set; }
public bool? VideoStatus { get; set; }
public string VideoDetail { get; set; }
public string PITFeedBack { get; set; }
public int ActivityID { get; set; }
public virtual ActivityModel Activity { get; set; }
public int ClientID { get; set; }
public virtual ClientModel Client { get; set; }
public int? SupportPlanID { get; set; }
public virtual SupportPlanModel SupportPlan { get; set; }
public int EmployeeID { get; set; }
public virtual Employee Employee { get; set; }
public bool FeedbackStatus { get; set; } = true;
virtual public List<FeedbackStepModel> FeedbackSteps { get; set; }
}
and和
public class FeedbackStepModel
{
[Key]
public int FeedbackStepID { get; set; }
public int FeedbackID { get; set; } = 0;
public int SupportPlanID { get; set; }
public int StepNumber { get; set; }
public string StepDetail { get; set; }
public string AchivmentStatus { get; set; }
public string AchivmentComment { get; set; }
}
This is the post method.这是post方法。 View returns Edited or Updated feedback and i just want to update the database with new data查看返回已编辑或更新的反馈,我只想用新数据更新数据库
[HttpPost]
public IActionResult Edit(FeedbackModel feedback)
{
if (ModelState.IsValid)
{
feedbackRepository.Save(feedback);
TempData["message"] = $"Feedback has been saved";
return RedirectToAction("Index");
}
}
after EDIT, I would like to save it...编辑后,我想保存它...
public void Save(FeedbackModel feedback)
{
if (feedback.FeedBackID == 0)
{
context.FeedbackModels.Add(feedback);
}
else
{
FeedbackModel dbEntry = context.FeedbackModels.Include(s => s.FeedbackSteps).FirstOrDefault(a => a.FeedBackID == feedback.FeedBackID);
if (dbEntry != null)
{
dbEntry.FeedBackID = feedback.FeedBackID;
dbEntry.FBDate = feedback.FBDate;
dbEntry.VideoStatus = feedback.VideoStatus;
dbEntry.VideoDetail = feedback.VideoDetail;
dbEntry.SupportPlanID = feedback.SupportPlanID;
dbEntry.ActivityID = feedback.ActivityID;
dbEntry.PITFeedBack = feedback.PITFeedBack;
dbEntry.ClientID = feedback.ClientID;
dbEntry.EmployeeID = feedback.EmployeeID;
dbEntry.FeedbackStatus = feedback.FeedbackStatus;
dbEntry.FeedbackSteps = feedback.FeedbackSteps;
}
}
context.SaveChanges();
}
But it gives me this error all the time但它一直给我这个错误
Message=The instance of entity type 'FeedbackStepModel' cannot be tracked because another instance with the key value '{FeedbackStepID: 1}' is already being tracked.
When attaching existing entities, ensure that only one entity instance with a given key value is attached.
Your FeedbackModel
update operation with children ( FeedbackSteps
) should be as follows:您FeedbackModel
更新操作 ( FeedbackSteps
) 应如下所示:
FeedbackModel dbEntry = context.FeedbackModels.Include(s => s.FeedbackSteps).FirstOrDefault(a => a.FeedBackID == feedback.FeedBackID);
if (dbEntry != null)
{
dbEntry.FeedBackID = feedback.FeedBackID;
dbEntry.FBDate = feedback.FBDate;
dbEntry.VideoStatus = feedback.VideoStatus;
dbEntry.VideoDetail = feedback.VideoDetail;
dbEntry.SupportPlanID = feedback.SupportPlanID;
dbEntry.ActivityID = feedback.ActivityID;
dbEntry.PITFeedBack = feedback.PITFeedBack;
dbEntry.ClientID = feedback.ClientID;
dbEntry.EmployeeID = feedback.EmployeeID;
dbEntry.FeedbackStatus = feedback.FeedbackStatus;
dbEntry.FeedbackSteps.Clear(); // First you have to clear the existing feedBackSteps
foreach(FeedbackStep feedBackStep in feedback.FeedbackSteps)
{
dbEntry.FeedbackSteps.Add(feedBackStep); // You have to add new and updated feedBackStep here.
}
}
If dbEntry.FeedbackSteps.Clear();
如果dbEntry.FeedbackSteps.Clear();
does not work (may be in EF Core 2.0 or lower Clear()
does not work) then replace dbEntry.FeedbackSteps.Clear();
不起作用(可能在 EF Core 2.0 或更低版本中Clear()
不起作用)然后替换dbEntry.FeedbackSteps.Clear();
with the following code:使用以下代码:
foreach(FeedbackStep feedbackStepToBeRemoved in dbEntry.FeedbackSteps)
{
context.Remove(feedbackStepToBeRemoved);
}
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