NullReferenceException when calling InsertOnSubmit in Linq to Sql.
- by Charlie
I'm trying to insert a new object into my database using LINQ to SQL but get a NullReferenceException when I call InsertOnSubmit() in the code snippet below. I'm passing in a derived class called FileUploadAudit, and all properties on the object are set.
public void Save(Audit audit)
{
try
{
using (ULNDataClassesDataContext dataContext = this.Connection.GetContext())
{
if (audit.AuditID > 0)
{
throw new RepositoryException(RepositoryExceptionCode.EntityAlreadyExists, string.Format("An audit entry with ID {0} already exists and cannot be updated.", audit.AuditID));
}
dataContext.Audits.InsertOnSubmit(audit);
dataContext.SubmitChanges();
}
}
catch (Exception ex)
{
if (ObjectFactory.GetInstance<IExceptionHandler>().HandleException(ex))
{
throw;
}
}
}
Here's the stack trace:
at System.Data.Linq.Table`1.InsertOnSubmit(TEntity entity)
at XXXX.XXXX.Repository.AuditRepository.Save(Audit audit)
C:\XXXX\AuditRepository.cs:line 25"
I've added to the Audit class like this:
public partial class Audit
{
public Audit(string message, ULNComponent component) : this()
{
this.Message = message;
this.DateTimeRecorded = DateTime.Now;
this.SetComponent(component);
this.ServerName = Environment.MachineName;
}
public bool IsError { get; set; }
public void SetComponent(ULNComponent component)
{
this.Component = Enum.GetName(typeof(ULNComponent), component);
}
}
And the derived FileUploadAudit looks like this:
public class FileUploadAudit : Audit
{
public FileUploadAudit(string message, ULNComponent component, Guid fileGuid, string originalFilename, string physicalFilename, HttpPostedFileBase postedFile)
: base(message, component)
{
this.FileGuid = fileGuid;
this.OriginalFilename = originalFilename;
this.PhysicalFileName = physicalFilename;
this.PostedFile = postedFile;
this.ValidationErrors = new List<string>();
}
public Guid FileGuid { get; set; }
public string OriginalFilename { get; set; }
public string PhysicalFileName { get; set; }
public HttpPostedFileBase PostedFile { get; set; }
public IList<string> ValidationErrors { get; set; }
}
Any ideas what the problem is? The closest question I could find to mine is here but my partial Audit class is calling the parameterless constructor in the generated code, and I still get the problem.
UPDATE:
This problem only occurs when I pass in the derived FileUploadAudit class, the Audit class works fine. The Audit class is generated as a linq to sql class and there are no Properties mapped to database fields in the derived class.
