Getting an instance of a SqlDataReader is a little different than the way you instantiate other ADO.NET objects. You must call ExecuteReader on a command object, like this:
The ExecuteReader method of the SqlCommand object, cmd , returns a SqlDataReader instance. Creating a SqlDataReader with the new operator doesn''''t do anything for you. As you learned in previous lessons, the SqlCommand object references the connection and the SQL statement necessary for the SqlDataReader to obtain data.
Previous lessons contained code that used a SqlDataReader, but the discussion was delayed so we could focus on the specific subject of that particular lesson. This lesson builds from what you''''ve seen and explains how to use the SqlDataReader.
注：本站部分文章源于互联网，版权归原作者所有！如有侵权，请原作者与本站联系，本站将立即删除！ 本站文章除特别注明外均可转载，但需注明出处！ [MinTao学以致用网] 
