Entity Framework - Saving child entities on update - entity-framework

Question

I have an Invoice entity and it has child InvoiceLog entities. When I first create an Invoice and add its InvoiceLog entities and save, it works fine. However, if I then edit the Invoice and try to add additional InvoiceLog entities, it completely ignores the new InvoiceLog entities and doesn't save them at all. Any ideas what I'm doing wrong?
//POST: /Secure/Invoices/Save/
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Save(Invoice invoice)
{
invoice.UpdateDate = DateTime.Now;
invoice.DeveloperID = Developer.DeveloperID;
invoice.InvoiceStatusID = (int)Enums.InvoiceStatus.Open;
if (invoice.InvoiceID == 0)
{//inserting new invoice.
DataContext.InvoiceData.Insert(invoice);
}
else
{//attaching existing invoice.
DataContext.InvoiceData.Attach(invoice);
}
AddHours(invoice);
//save changes.
DataContext.SaveChanges();
//redirect to invoice list.
return RedirectToAction("Index");
}
private void AddHours(Invoice invoice)
{
//get existing logs.
IQueryable<InvoiceLog> existingLogs = null;
if(invoice.InvoiceID > 0)
{
existingLogs = DataContext.InvoiceData.GetLogs(invoice.InvoiceID);
}
//create new logs.
var numDays = invoice.EndDate.Subtract(invoice.StartDate).TotalDays;
for (int k = 0; k <= numDays; k++)
{
//check if log already exists.
var existingLog = existingLogs.ToList().FindIndex(l => l.LogDate == invoice.StartDate.AddDays(k));
if (existingLog == -1)
{
//add new log.
var log = new InvoiceLog();
log.CreateDate = DateTime.Now;
log.UpdateDate = DateTime.Now;
log.Hours = 0;
log.InvoiceID = invoice.InvoiceID;
log.LogDate = invoice.StartDate.AddDays(k);
invoice.InvoiceLogs.Add(log);
}
}
}
Thanks,
Justin

Answer 1

You can try to add InvoiceLogs items before attaching the invoice:
else
{//attaching existing invoice.
AddHours(invoice);
DataContext.InvoiceData.Attach(invoice);
}