The DataAdapter must be configured one way or another--unlike ADO classic
where the action commands were generated on the fly, in ADO.NET the
responsibility to create the InsertCommand, UpdateCommand and DeleteCommand
is yours. Of course, you can relegate this responsibility to the Visual
Studio Data Source code generator which uses the CommandBuilder. This
approach closely approximates the ADO classic approach but many developers
soon grow out of it as it has a number of significant limitations.
I discuss how to build the TableAdapter in Chapter 6 and elsewhere...
--
____________________________________
William (Bill) Vaughn
Author, Mentor, Consultant
Microsoft MVP
INETA Speaker
www.betav.com/blog/billva
www.betav.com
Please reply only to the newsgroup so that others can benefit.
This posting is provided "AS IS" with no warranties, and confers no rights.
__________________________________
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Hitchhiker's Guide to Visual Studio and SQL Server (7th Edition)
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-----------------------------------------------------------------------------------------------------------------------
<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi,
> I'd like to take a table in a database and modify some rows and delete
> some others. So I created a dataset, and tried to make modifications
> to one of its tables, and then I tried to send it back to the
> database. But I got an error message: "update requires a valid
> UpdateCommand when passed datarow collection with Modified rows."
> Here is my code fragment. What's missing? I looked at the Microsoft
> MSDN pages, but they often seem to explain one method at a time,
> without showing how to use the methods together to accomplish a task.
> -- HA
>
> Function PlayWithExperimentalTable() As Boolean
> Dim myOleDbDataAdapter As OleDbDataAdapter
> Dim myDataSet As DataSet = New DataSet
> Dim ChangesDataSet As DataSet = New DataSet
> Dim myDataTable As DataTable = New DataTable
> Dim myOleDbconnection As OleDbConnection
> Dim retval As Boolean
> Dim RowCount As Integer
> Dim Index As Integer
> Dim myDisplayRow As DataRow
> Dim strSQL As String
> Dim FirstName As String
> Dim LastName As String
> Dim Age As Integer
>
> strSQL = "Select * from ExperimentalTable"
>
> If ConnectToAddinDbase(constStockDatabase, myOleDbconnection)
> Then
> Try
> myOleDbDataAdapter = New OleDbDataAdapter(strSQL,
> myOleDbconnection)
> myOleDbDataAdapter.TableMappings.Add("Table",
> "ExperimentalTable")
> myOleDbDataAdapter.Fill(myDataSet)
> myDataTable = myDataSet.Tables("ExperimentalTable")
> RowCount = myDataTable.Rows.Count
> If RowCount = 0 Then
> ErrorBox("No Records found in experimentalTable")
> Else
> For Index = 0 To RowCount - 1
> myDisplayRow = myDataTable.Rows(Index)
> FirstName = myDisplayRow("FirstName").ToString
> LastName = myDisplayRow("lastname").ToString
> Age = CInt(myDisplayRow("Age"))
> myDataTable.Rows(Index)("FirstName") =
> FirstName & "-" & Left(FirstName, 1) & "junior"
> If Index = 5 Then
> myDataTable.Rows(Index).Delete()
> End If
> Next
> If myDataSet.HasChanges(DataRowState.Modified
> Or DataRowState.Added Or DataRowState.Deleted) Then
>
> ' Use GetChanges to extract subset.
> ChangesDataSet =
> myDataSet.GetChanges(DataRowState.Deleted Or _
> DataRowState.Modified Or
> DataRowState.Added)
>
> myOleDbDataAdapter.Update(ChangesDataSet)
> End If
> End If
> retval = True
> Catch ex As Exception
> InternalErrorBox("Error Reading From TS2IBSymbol.
> Internal Message: " & ex.Message & ". routine was
> 'PlayWithExperimentalTable', sql statement was " & strSQL)
> retval = False
> Finally
> myOleDbconnection.Close()
> myOleDbconnection = Nothing
> End Try
> Return (retval)
> Else
> Return (False)
> End If
> End Function
>
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