DevForce Community Forum : Persistence of entities http://www.ideablade.com/forum/ This is an XML content feed of; DevForce Community Forum : DevForce Classic : Persistence of entities Thu, 11 Jun 2026 06:24:11 -700 Fri, 07 Mar 2008 10:28:39 -700 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 9.69 360 www.ideablade.com/forum/RSS_post_feed.asp?TID=482 DevForce Community Forum http://www.ideablade.com/forum/forum_images/IdeaBlade_logo_tm.png http://www.ideablade.com/forum/ Persistence of entities : Here is the tutorial on Persistence... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2661#2661 Author: davidklitzke
Subject: 482
Posted: 07-Mar-2008 at 10:28am

Here is the tutorial on Persistence Order:
 
uploads/20080307_132827_Persistence_Ord.zip
]]> Fri, 07 Mar 2008 10:28:39 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2661#2661 Persistence of entities : Before the Business Objects are... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2660#2660 Author: davidklitzke
Subject: 482
Posted: 07-Mar-2008 at 10:23am

Before the Business Objects are saved to the database, all of the temporary IDs are converted to permanent IDs.  This means not only fixing up the IDs of the newly created objects, but all references to these objects.  However, DevForce can only do this if it knows about the relationship between the two Business Objects.  I think that what is happening is that you have not declared this relationship.
 
To prove that DEvForce does do this correctly,  take the IdeaBlade Tutorial Database, and write a little application that creates an order and an order detail that belongs to the  order.  Save the two new business objects.  You will find that you do not have a problem.
 
 
]]> Fri, 07 Mar 2008 10:23:25 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2660#2660 Persistence of entities : After further investigation, I... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2658#2658 Author: Hawkaye1
Subject: 482
Posted: 07-Mar-2008 at 9:29am

After further investigation, I found that the problem is tied to the IdGenerator. I use the IdGenerator to generate the next order number as well as the Unique Id. Everything works fine until I add the Order to the CustomerOrder collection. I show the Unique Id to be fine, it is the OrderNo (-1) that get saved to the database.

 
    Public Shared Function Create(ByVal pManager As PersistenceManager, ByVal pCustomer As Customer) As Order
        Dim aOrder As Order
        aOrder = pManager.CreateEntity(Of Order)()
        ' if this object type requires a unique id and you have implemented
        ' the IIdGenerator interface implement the following line
        pManager.GenerateId(aOrder, Invoice.IdEntityColumn)
        pManager.GenerateId(aOrder, Order.OrderNoEntityColumn)
        ' Add custom code here
        aOrder.AddToManager()
        aOrder.RowVersion = 0
        aOrder.Customer = pCustomer
        aOrder.TermId = 1
        aOrder.OrderTypeId = 1
        Return aOrder   
   End Function
Database Row: (OrderNo in Red)
      
28364-1296084123111045.0000NULLNULLFalseNULLFalseFalseNULLNULL0
 
NextId Table
 
Name             NextId     DefaultGroupSize
Trip150011
Order428691
Pay10471
Customer65991
Driver52511
NULLNULLNULL


Edited by Hawkaye1 - 07-Mar-2008 at 9:30am]]> Fri, 07 Mar 2008 09:29:20 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2658#2658 Persistence of entities : When I save changes, I get the... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2656#2656 Author: Hawkaye1
Subject: 482
Posted: 07-Mar-2008 at 6:45am

When I save changes, I get the error:
 
A first chance exception of type 'IdeaBlade.Persistence.PersistenceManagerSaveException' occurred in IdeaBlade.Persistence.dll
Additional information: Save failed - Collection was modified; enumeration operation may not execute.
 
All I have to do to get the error (Example: Create a new Order, Create a new OrderDetail, Then add the Order to the CustomerOrders collection.)
 
Order.Create(persMgr)
OrderDetail.Create(persMgr, mOrder)
mOrderBS.MoveLast()
currentOrder = CType(OrderBS.Current, Order)
mCustomerOrder = CType(CustomerOrderBS.Current, CustomerOrder)
mCustomerOrder.Order = currentOrder
 
Dim pMgrSave As SaveHelper = New SaveHelper(pm)
Try
If pMgrSave.SaveAll Then
DevExpress.XtraEditors.XtraMessageBox.Show("Information Saved", "Saved", MessageBoxButtons.OK, MessageBoxIcon.Information)
Else
DevExpress.XtraEditors.XtraMessageBox.Show("Nothing to Save", "No changes", MessageBoxButtons.OK, MessageBoxIcon.Information)
End If
Catch ex As Exception
DevExpress.XtraEditors.XtraMessageBox.Show("An exception of type " & ex.GetType().ToString() & _
" was encountered. ")
End Try
This is my save function:
 
Public Class SaveHelper
Private pMgr As PersistenceManager
 
Public Sub New(ByVal persMgr As PersistenceManager)
pMgr = persMgr
End Sub
 
Public Function SaveAll() As Boolean
Dim result As SaveResult
 
If pMgr.HasChanges Then
Try
result = pMgr.SaveChanges()
If result.Ok Then
Return True
End If
Catch ex As Exception
DevExpress.XtraEditors.XtraMessageBox.Show("An exception of type " & ex.GetType().ToString() & _
" was encountered. ")
End Try
End If
Return False
End Function
 
If I retry the save, it will save the tempId to the record and save it to the database. This only happens if I create a new Order
Yes, I would like an example to modify the persistence order.
]]> Fri, 07 Mar 2008 06:45:48 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2656#2656 Persistence of entities : Persistemce Order is a property... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2640#2640 Author: davidklitzke
Subject: 482
Posted: 05-Mar-2008 at 9:25am

Persistemce Order is a property of the Save operation and is not a property of the Business Objects themselves.  We used to include a tutorial on Persistence Order, but after we implemented automatic calculaion of a default Persistence Order a few years ago, we dropped the tutorial since we couldn't find any real life examples of situations where we would want to modify the Persistence Order.
 
Why are you trying to modify thE Default Persistence Order?  BTW, Your error message about modifying a readonly entity has nothing to do with Persistence Order,
 
I can send you an example of modifying the Persistence Order if you wish.
]]> Wed, 05 Mar 2008 09:25:58 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2640#2640 Persistence of entities : Do you have an example of how... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2639#2639 Author: Hawkaye1
Subject: 482
Posted: 05-Mar-2008 at 8:37am

Do you have an example of how to modify the persistence order, any attempt I have made says the colloection is readonly.]]> Wed, 05 Mar 2008 08:37:01 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=2639#2639 Persistence of entities : Thanks, regaring those rare cases,... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=1561#1561 Author: Yaron
Subject: 482
Posted: 10-Oct-2007 at 9:21pm

Thanks, regaring those rare cases, Has anybody been able to Isolate those scenarios, it will help alot if I can know them before building my Save methods

 
 
]]> Wed, 10 Oct 2007 21:21:59 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=1561#1561 Persistence of entities : The most likely cause is that... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=1537#1537 Author: davidklitzke
Subject: 482
Posted: 10-Oct-2007 at 11:30am

The most likely cause is that the Persistence Order is incorrect.  The Persistence Order is by default set automatically by the Persistence Manager through the use of a "reverse topological sort".

 

If the Persistence Order is incorrect, you will need to override it with your own order using the SaveOptions of SaveChanges.

 
You might also try using the PersistenceManager.ForceIdFixUp() to resolve both parent and child tables’ IDs/keys first in an atemmpt to improve the behavior of the reverse topological sort.
 
There are some rare cases where you cannot solve the problem through Persistence Order.  In these cases, you will have to solve the problem by performing a 2-step save.
]]> Wed, 10 Oct 2007 11:30:00 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=1537#1537 Persistence of entities : I observed what appears strange... http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=1501#1501 Author: Yaron
Subject: 482
Posted: 09-Oct-2007 at 9:56am

I observed what appears strange behaviour.

I have a simple invoice & stock inventory system, Generate invoice and when saving invoice details - adjust the Qty In stock for the store,
what I noticed is that the Invoice Data (rowstate = 'Added') saves fine,but the ProductStore entity (where I store the qty is stock) which has RowState = 'Modified' looses the changes before saving.
I used the PM.SaveChanges method.
 
however is I 'split' the save operation i.e. save the StockLevels (modified) rows first, and on a second save operation save the Invoice Details. all works well, here is what I mean
  
Scenario 1 : SaveData(AllChanges) don't work
Scenario 2 : SaveData(InvoiceData)
                    SaveData(StockLevels) don't work
Scenario 3:  SaveData(StockLevels)
                    SaveData(InvoiceData) works well
 
Can anybody help?
]]> Tue, 09 Oct 2007 09:56:20 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=482&PID=1501#1501