public void UpdateCustomerID(Int32 newId, Int32 oldId, String connectionString)
{
   TdConnection cn = null;
   TdTransaction tran = null;
   try
   {
       // Open a session to Teradata.
       cn = new TdConnection(connectionString);
       cn.Open();
            
       // Begin an explicit transaction.
       tran = cn.BeginTransaction();
             
       // Create a command to execute DML statements.  
       TdCommand cmd = cn.CreateCommand();
       cmd.Transaction = tran;
            
       // Update the customer table.
       cmd.CommandText = String.Format(“Update Customer Set CustomerID = ‘{0}’ "
                                       “where CustomerID = ‘{1}’”, newId, oldId);
       cmd.ExecuteNonQuery();
            
       // Update the order table.
       cmd.CommandText = String.Format(“Update Order Set CustomerID = ‘{0}’ “
                                      “where CusomerID = ‘{1}’”, newId, oldId);
       cmd.ExecuteNonQuery();
            
       // Commit the transaction.
       tran.Commit();
       tran.Dispose();
       tran = null;
            
       // Close the command.
       cmd.Dispose();
   }
   catch(TdException e)
   {
       if (null != tran)
       {
           tran.Rollback();
           tran.Dispose();
           tran = null;
       }
   }
   finally
   {
       if (null != cn)
       {
           cn.Close();
           cn = null;
       }
   }
}