table.DefaultView.RowFilter = "DISTINCT Level"

    
    private static void DemonstrateDataView()
    {
    // Retrieve a DataTable from the AdventureWorks sample database.
    // connectionString is assumed to be a valid connection string.
    SqlDataAdapter adapter = new SqlDataAdapter(
        "SELECT FirstName, LastName, EmailAddress " +
        "FROM Person.Contact WHERE FirstName LIKE 'Mich%'", 
           GetConnectionString());
    DataTable table = new DataTable();

    adapter.Fill(table);

    // Create a new DataTable based on the DataView,
    // requesting only two columns with distinct values
    // in the columns.
    DataView view = table.DefaultView;
    DataTable newTable = view.ToTable("UniqueLastNames", true, "FirstName", "LastName");
    }