Question

我有一种方法可以接受表单提交和提交答案。为了将提交的答案保存到数据库中；我需要使用提交的参考ID设置提交答案。

我正在尝试执行此操作，但收到标题中列出的错误： “由于对象的当前状态，操作无效”，我不确定为什么。

在调整任何值之前，我尝试将所有内容保存到数据库；但这似乎无济于事。我收到另一个错误消息，说我正在尝试删除外键。

我想这是数据库上下文问题。

public FormSubmission AddSubmission(FormSubmission submission, List<FormSubmissionAnswer> submissionAnswers, int CustomerId, string CustomerName)
    {
        Form form = GetForm(submission.FormId.ToString());
        //set submission values
        submission.FormTitle = form.Title1;
        submission.DateSubmitted = DateTime.Now;
        if (CustomerId > 0)
            submission.PSMCustomerId = CustomerId;
        submission.CustomerName = CustomerName;
        base.SubscriptionDB.FormSubmissions.InsertOnSubmit(submission);
        base.SubscriptionDB.SubmitChanges();

        //need to update the submission answers FormSubmissionId            
        foreach (FormSubmissionAnswer answer in submissionAnswers)
            answer.FormSubmissionId = submission.Id; //erroring here

      base.SubscriptionDB.FormSubmissionAnswers.InsertAllOnSubmit(submissionAnswers);
        base.SubscriptionDB.SubmitChanges();

}

Answer 1

您的FormSubmission和FormSubmissionAnswer实体是什么样的？我假设FormSubmission具有某种IEnumerable属性来表示两者之间的关系。在进行初始提交更改之前，尝试将答案对象添加到列表中：

submission.CustomerName = CustomerName;
submission.FormSubmissionAnswers.AddRange(submissionAnswers);
base.SubscriptionDB.FormSubmissions.InsertOnSubmit(submission);
base.SubscriptionDB.SubmitChanges();

我相信EF应该自动生成PK并正确分配正确的FK。然后，您甚至都不需要这样做：

//need to update the submission answers FormSubmissionId            
foreach (FormSubmissionAnswer answer in submissionAnswers)
    answer.FormSubmissionId = submission.Id; //erroring here

base.SubscriptionDB.FormSubmissionAnswers.InsertAllOnSubmit(submissionAnswers);
base.SubscriptionDB.SubmitChanges();

Answer 2

代替

foreach (FormSubmissionAnswer answer in submissionAnswers)
            answer.FormSubmissionId = submission.Id; //erroring here

尝试

foreach (FormSubmissionAnswer answer in submissionAnswers)
            submission.FormSubmissionAnswers.Add(answer);

在结束通话中 base.SubscriptionDB.SubmitChanges（）;

base.SubscriptionDB.FormSubmissions.InsertOnSubmit（submission）; base.SubscriptionDB.SubmitChanges（）; //从FormSubmission删除，而只能使用一次。这应该可以解决您的问题。

您的最终代码应如下所示

Form form = GetForm(submission.FormId.ToString());
        //set submission values
        submission.FormTitle = form.Title1;
        submission.DateSubmitted = DateTime.Now;
        if (CustomerId > 0)
            submission.PSMCustomerId = CustomerId;
        submission.CustomerName = CustomerName;
        base.SubscriptionDB.FormSubmissions.InsertOnSubmit(submission);
        
        //need to update the submission answers FormSubmissionId            
        foreach (FormSubmissionAnswer answer in submissionAnswers)
            submission.FormSubmissionAnswers.Add(answer); 
   
        base.SubscriptionDB.SubmitChanges();

我假设您具有适当的实体关系。

由于C＃实体框架中对象的当前状态，因此操作无效

2 个答案: