Question

我尝试了许多不同的方法来删除IncidentDescriptions DBContext的某些行，但是我真的无法弄清楚这一点。在调试窗口中，从该行显示的是一个ID和一个打印出来的描述，所以我知道有一个行被选中并且不会成为问题：

foreach (var desc in DB.IncidentDescriptions.Where(d => d.AccidentHeaderId == supervisor.AccidentHeaderId)) {
    System.Diagnostics.Debug.WriteLine(desc.Id + " " + desc.Description);
}

控制器：

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include = @"Id,AccidentHeaderId,DateLastModified,LastModifiedUsername,DateAccidentReported,EmployeeReported,ReportedInSameShift
,DateReportedOutsideShift,AccidentLocation,IncidentDate,IncidentTime,MedicalAttention,Clinic,ReturnToWork,DrugScreenPapers,DamageDesc,MissDollarEst,ActsContributed
,CorrectiveActions,DiscusedWithEmployee,WorkOrderComplete,Comments,AccidentNarrative,FirstName,LastName,DrugTested,FirstNameReportedTo,LastNameReportedTo
,DateInvestigationStarted,TimeInvestigationStarted,DeptManager, HospitalName,
BodyPartXREF, EmployeesInvolved, IncidentDescriptions, InjuryDescriptionXREF, UnsafeActXREF, WitnessesInvolved
")] AccidentSupervisorViewModel supervisor, List<string> SelectedUnsafeActs, int? SelectedLocation, List<string>DescriptionUser, List<string>DescriptionPosition)
{
    if (ModelState.IsValid)
    {
        using (DB)
        {
            using (var contextTransaction = DB.Database.BeginTransaction())
            {
                try
                {
                foreach (var desc in DB.IncidentDescriptions.Where(d => d.AccidentHeaderId == supervisor.AccidentHeaderId)) {
                    System.Diagnostics.Debug.WriteLine(desc.Id + " " + desc.Description);
                }
                DB.IncidentDescriptions.Remove(DB.IncidentDescriptions.FirstOrDefault(d => d.AccidentHeaderId == supervisor.AccidentHeaderId));
                DB.SaveChanges();
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(ex.Message);
                    contextTransaction.Rollback();
                }
            }
        }
        return RedirectToAction("Index", "Incident"); 
    }
    return View(supervisor);
}

Answer 1

您不是committing your transaction。顺便说一句，EF已经实施了工作单元，因此可能会过大。另外，我会用Single（）代替FirstOrDefault（）-如果什么也没找到，您想要一个异常。另外，不确定是否需要绑定。由于您具有视图模型，因此只会传递这些值。

我将正文重写为：

typeof AuthenticationService

MVC 5-尝试使用linq删除行时，没有错误，并且未删除该行。为什么？

1 个答案: