foreach with SqlDataReader?

I have the following code:

SqlDataReader reader = getAddressQuery.sqlReader;
while (reader.Read())
{
    foreach (Object ob in reader)
    {
        someText.InnerText = someText.InnerText + " " + ob.ToString();
    }
}

The code in the foreach loop does not execute. However, I can do this:

SqlDataReader reader = getAddressQuery.sqlReader;
while (reader.Read())
{
    someText.InnerText = reader[0].ToString();
}

Which works.

Obviously I could achieve the same result using a regular for loop rather than a foreach loop, but I think the foreach syntax is clearer, so I use it when possible.

What has gone wrong here? Are foreach loops in c# not as flexible as in more high level languages?