Will putting a “using” statement around a DataReader close it?

Question

I usually write my DataReader code like this:

try
{
    dr = cmd.ExecuteReader(CommandBehavior.SingleResult);
    while (dr.Read())
    {
               


        

Answer 1

Typically, using() calls Dispose() and that calls close() in turn.

In case of a DataReader, the Close is called only when CommandBehavior.CloseConnection is set (see comments of this article http://weblogs.asp.net/joseguay/archive/2008/07/22/ensure-proper-closure-amp-disposal-of-a-datareader.aspx).

EDIT: This article says something interesting:

The Close() method on the SqlDataReader calls an InternalClose() method, which does not call Dispose. Note that previously we stated the correct way to do this was to have your close call dispose. To make it even more confusing the Dispose() method actually calls the Close() method so for this object the order is reversed.