Tengo una serie de elementos secundarios de una tabla, que deseo eliminar y luego agregar los nuevos.
No me importa el rendimiento, porque es una operación no frecuente.Cómo eliminar y luego agregar elementos secundarios en LINQ to SQL
¿Cómo debo hacerlo? He tratado Order.items.clear()
y Order.Items.Remove(x)
pero ambos me dan excepciones
código simplificado:
Dim db As New MainDataDataContext
dim o as Order = (From Order In db.Orders Where Order.OrderID = OrderID).FirstOrDefault
''//this will return "An attempt was made to remove a
''//relationship between a Order and a OrderItem.
''//However, one of the relationship's foreign keys
''//(Order.OrderID) cannot be set to null." exception
o.Items.Clear()
''//and this will return "EntitySet was modified during enumeration." exception
For Each oItem As OrderItem In o.Items
o.items.Remove(oItem)
Next
For Each item As ListViewItem In listViewOrderItems.Items
If item.ItemType = ListViewItemType.DataItem Then
Dim oItem As New OrderItem
oItem.OrderID = OrderID
oItem.Product = CType(item.FindControl("txtProduct"), TextBox).Text
oItem.Quantity = CType(item.FindControl("txtQuantity"), TextBox).Text
Order.items.Add(oItem)
End If
Next
db.SubmitChanges()