如何处理 OData Client 中的一对多关系？

Question

我有一个 Web Api 2 服务 和一个 WPF OData 客户端，我正在使用 Crystal 报告.

我有两个表（教师，主题）具有一对多他们之间的关系。 我正在尝试让 Subjects 反对 Teacher_Id.

以下是我使用的代码：

private string ServiceUri = "http://localhost:50623/odata";
    private void pge_TeacherReportPage_Loaded(object sender, RoutedEventArgs e)
    {
        var Container = new Default.Container(new Uri(ServiceUri));
        ReportDocument report = new ReportDocument();
        report.Load("../../TeacherCrystalReport.rpt");
        var Teacher = from c in Container.Teachers
                      select new
                      {
                         Name = c.Name,
                         FatherName = c.FatherName,
                         ContactNo = c.ContactNo,
                         Address = c.Address,
                         Religion = c.Religion,
                         CNIC = c.CNIC,
                         Status = c.Status,
                         UserName = c.UserName,
                         Subjects = c.Subjects.Where(s=> s.Teacher_Id == c.Teacher_Id).SingleOrDefault()
                      };
        report.SetDataSource(Teacher);            
        rpt_Teacher.ViewerCore.ReportSource = report;
    }

但我无法这样做，因为我收到以下 Exception:

An unhandled exception of type 'System.NotSupportedException' occurred in Microsoft.OData.Client.dll

Additional information: Constructing or initializing instances of the type <>f__AnonymousType1`9[System.String,System.String,System.String,System.String,System.String,System.String,System.String,System.String,QuizSystemClient.RestApiOData.Models.Subject] with the expression c.Subjects.Where(s => (s.Teacher_Id == c.Teacher_Id)).SingleOrDefault() is not supported.

请告诉我该如何解决？

Answer 1

我的问题已解决，我对代码进行了以下更改。

    var Teacher = from c in Container.Teachers
                      select new
                      {
                         Name = c.Name,
                         FatherName = c.FatherName,
                         ContactNo = c.ContactNo,
                         Address = c.Address,
                         Religion = c.Religion,
                         CNIC = c.CNIC,
                         Status = c.Status,
                         UserName = c.UserName,
                         //I had made changes in the following code:
                         Subjects = c.Subjects.Select(s=>s.Subject_Name).FirstOrDefault()
                      };