How to Lock a Table in SQL SERVER Using VB.NET

The following code shows how to Lock a Table in SQL SERVER Using VB.NET

Step1:Create Window based project and select language as VB.NET
Step2:Add a button control named CmdFill set its properties Text="Fill" and a datagrid named Datagrid1
Step3:Implement the following Code

 Dim txn As SqlTransaction
    Dim ds As New DataSet
    Dim con As New SqlConnection("Data source=sourcename;Initial catalog=Northwind;uid=gopi;pwd=gopi")
    Private Sub CmdFill_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CmdFill.Click
        con.Open()
        adp.Fill(ds, "Customers")
        txn = con.BeginTransaction(IsolationLevel.RepeatableRead)
        adp.SelectCommand.Transaction = txn
        adp.Fill(ds)
        DataGridView1.DataSource = ds
        DataGridView1.DataMember = "Customers"
    End Sub