Article ID: 310370
Article Last Modified on 6/29/2004
APPLIES TO
- Microsoft ADO.NET 1.1
- Microsoft ADO.NET 1.0
- Microsoft Visual Basic .NET 2003 Standard Edition
- Microsoft Visual Basic .NET 2002 Standard Edition
This article was previously published under Q310370
This article refers to the following Microsoft .NET Framework Class Library namespaces:
- System.Data.SqlClient
- System.Console
IN THIS TASK
SUMMARY
You can use ADO.NET DataTable objects to delete rows and mark them as "Deleted." This article demonstrates how to retrieve the values of a row whose DataRowState enumeration is set to DataRowState.Deleted.
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Description of the Technique
You can use the DataRowVersion.Original enumeration value to retrieve the values of a row that has the DataRowState.Deleted enumeration value. You must use DataRowVersion.Original because the values of a deleted row are not available for the current state (DataRowVersion.Current).
If you try to reference current column values of a DataRow object that has a RowState property value of DataRowState.Deleted, you receive the following error message:
Steps to Build the Sample
The sample code in this section demonstrates how to reproduce the preceding error. This sample also demonstrates how to use DataRowVersion.Original to obtain the column values of the deleted row.
- Create a new Visual Basic Console Application project.
Delete the default code, and add the following code to the Module1 code module:
Imports System.Data.SqlClient Imports Console = System.Console Module Module1 Sub Main() Dim response As String Dim myDataSet As New DataSet() Dim myDataRow As DataRow Dim newDataSet As DataSet Dim rowsInError As DataRow() Dim newTable As DataTable Dim newCol As DataColumn Dim i As Integer Dim myCn As New SqlConnection() myCn.ConnectionString = "Server=mySQLServer;User ID=sa;Password=mypassword;" & _ "Initial Catalog=Northwind;" Dim myDACust As New SqlDataAdapter("Select * From Customers", myCn) Dim myCmdBlder As New SqlCommandBuilder(myDACust) myCn.Open() myDACust.MissingSchemaAction = MissingSchemaAction.AddWithKey myDACust.Fill(myDataSet, "Customers") myDataSet.Tables("Customers").Rows(0).Delete() Dim delRow As DataRow If myDataSet.HasChanges(DataRowState.Deleted) Then newDataSet = myDataSet.GetChanges(DataRowState.Deleted) If (Not newDataSet.HasErrors) Then delRow = newDataSet.Tables("Customers").Rows(0) ' The following line generates the exception: Console.WriteLine(delRow(0)) ' To resolve this problem, comment the previous line, ' and uncomment the following line. ' Console.WriteLine(delRow(0, DataRowVersion.Original)) End If End If If myCn.State = ConnectionState.Open Then myCn.Close() End If myCn = Nothing Console.WriteLine("Update was processed successfully!") Console.ReadLine() End Sub End Module
- Modify the parameters of the ConnectionString property of the SqlConnection object as appropriate for your environment.
- In the Microsoft Visual Studio .NET Integrated Development Environment (IDE), on the Debug menu, click Run Without Debugging to run the code. A console window displays the "Update was processed successfully!" message if Visual Studio does not encounter any errors.
- Press any key to dismiss the Console window and stop the application.
REFERENCES
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
172375 How To Undo Updates for a Single Row with CancelBatch
For more information, see the "Row States and Row Versions" topic and other topics in the Microsoft .NET Framework documentation.
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Keywords: kbhowtomaster kbsqlclient kbsystemdata kbconsole KB310370