How Do I Send Modified And Added Rows Between Two Servers That Implement The Same Database ?

See more:

VB

SQL

What I Want To Do :

i have a database with tables :
Items
ItemsBarcodes
Invoices
InvoiceDetails
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the same database exists on server A and server B
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only applications working on server A are allowed to add/modify rows to items and itemsBarcodes tables
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i need a way to programatically send a file from application working on sever A that contains the added/modified data to the application that works on server B so that it can update the items and itemsBarcodes datatables

How I am Currently Doing It

1-i export the data from server A to Files like this :

Try
            strm = Nothing

            strm = New FileStream(ItemsFileName, FileMode.OpenOrCreate)
            srItems.Serialize(strm, ds.Items)
            strm.Close()
            strm = Nothing

            strm = New FileStream(ItemsACFileName, FileMode.OpenOrCreate)
            srItemsAc.Serialize(strm, ds.ItemsAC)
            strm.Close()
            strm = Nothing

            strm = New FileStream(ItemsTagFileName, FileMode.OpenOrCreate)
            srItemsTag.Serialize(strm, ds.ItemsTag)
            strm.Close()
            strm = Nothing

            strm = New FileStream(BarcodesFileName, FileMode.OpenOrCreate)
            srBarcodes.Serialize(strm, ds.Barcodes)
            strm.Close()
            frmBase.ntfy.ShowBalloonTip(5000, "Done", "Items Count = " & ds.Items.Count, ToolTipIcon.Info)
        Catch ex As Exception
            frmBase.ntfy.ShowBalloonTip(5000, "Error", ex.Message, ToolTipIcon.Error)
        End Try

2-the i try to load the data back at server B like this :

Dim ds2 As New UltimatePharmaDataSet

Try

           strm = Nothing
           strm = New FileStream(ItemsFileName, FileMode.OpenOrCreate)
           source = "Items"
           ds2.ReadXml(strm)
           strm.Close()


           strm = Nothing
           strm = New FileStream(ItemsACFileName, FileMode.OpenOrCreate)
           source = "ItemsAC"
           ds2.ReadXml(strm)
           strm.Close()


           strm = Nothing
           strm = New FileStream(ItemsTagFileName, FileMode.OpenOrCreate)
           source = "ItemsTag"
           ds2.ReadXml(strm)
           strm.Close()


           strm = Nothing
           strm = New FileStream(BarcodesFileName, FileMode.OpenOrCreate)
           source = "Barcodes"
           ds2.ReadXml(strm)
           strm.Close()
           source = ""

           For Each r As UltimatePharmaDataSet.ItemsRow In ds2.Items
               source = "Items" & r.ItemName
               If ds.Items.FindByItemID(r.ItemID) Is Nothing Then

                   r.SetAdded()
               Else

                   r.SetModified()


               End If
               r.EndEdit()
           Next

           For Each r As UltimatePharmaDataSet.BarcodesRow In ds2.Barcodes
               source = "Barcodes" & r.ItemsRow.ItemName & " " & r.Barcode
               If ds.Barcodes.FindByItemIDBarcode(r.ItemID, r.Barcode) Is Nothing Then

                   r.SetAdded()
               End If
               r.EndEdit()
           Next
           source = ""
           tadMngr.UpdateAll(ds2)
           frmBase.ntfy.ShowBalloonTip(5000, "Done", "Items Count = " & ds2.Items.Count, ToolTipIcon.Info)
       Catch ex As Exception
           frmBase.ntfy.ShowBalloonTip(5000, "Error", ex.Message & source, ToolTipIcon.Error)
       Finally
           strm.Close()
       End Try

where ds represents the original dataset on server B
and ds2 is the dataset read from the files sent from server A

The Problem Is :
when the tadMngr ( the TableAdapterManager ) tries to updateAll(ds2)
i get the error message :
concurrency violation the updateCommand affected 0 of the expected 1 record

i used SQL profiler to find out which rows cause the error
turns out only rows modified in server A or rows that have related rows modified raise this error

the error message is gone after i ignored those rows
but that is not the solution at all

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can any body help by pointing out what's wrong with my method or point me in the direction of a better method to achieve the same goal ?

thanks every body