phattrienweb

SqlConnection firstConnection = new SqlConnection(connectionString);
firstConnection.Open();

SqlConnection secondConnection = new SqlConnection(connectionString);
secondConnection.Open();

try
{
  using (SqlCommand firstCommand = new SqlCommand(firstQuery, firstConnection))
  {
    ...
    using (SqlDataReader firstReader = firstCommand.ExecuteReader())
    {
      while (firstReader.Read())
      {
        ...
        using (SqlCommand secondCommand = new SqlCommand(secondQuery, secondConnection))
        {
          ...
          using (SqlDataReader secondReader = secondCommand.ExecuteReader())
          {
            while (secondReader.Read())
            {
              ...
            }
          }
        }
      }
    }
  }
}
catch (Exception ex)
{
  ...
}

firstConnection.Close();
secondConnection.Close();