return stored proc results as XML

Question

I am writing an interface in a Web service that returns XML output. The output is queried from a MS SQL database by calling stored procedure. While the stored procedure itself is not returning XML, and I don't have any control over it, I need to return the result set as XML.

Right now, I'm using XmlWriter. Is there an easier, elegant way to do this?

        StringBuilder sbLog = new StringBuilder();
        XmlWriter writer = XmlWriter.Create(sbLog);
        writer.WriteStartDocument();
        writer.WriteStartElement("LogSet");

        while (sqlRdr.Read())
        {
            writer.WriteStartElement("Log");

            writer.WriteStartElement("EntryID");
            writer.WriteValue(sqlRdr["EntryID"].ToString());
            writer.WriteEndElement();

           //and so on

Answer 1

Yeah XDocument is probably a cleaner interface. It would look something like this:

var doc = new XDocument(
    new XElement("LogSet",
        new XElement("EntryID", sqlRdr["EntryID"].ToString()),
        new XElement(...)
    )
);

// save it to a file
doc.Save(pathToDoc);

// or just return it
return doc.ToString();

Answer 2

I'm not sure about it's elegance (I guess that partially depends on how many times you need to reproduce this sort of thing in your code), but I wrote an XmlDataReader a while back that converts tabular data in an IDataReader into an Xml result without the need to create a secondary document/string. As WebServices could return an XmlNode (rather than XmlReader) the second class XmlNodeFactory does that conversion.

Here is the Gist for XmlDataReader And for the XmlNodeFactory

Usage is something like:

[WebMethod]
public XmlNode GetFeaturedItems(string storeId)
{
    var xmlReader = new XmlDataReader( 
        _db.GetFeaturedItems(storeId), 
        MyXmlNames.FeaturedItemsNamespace)
        {
            IncludeIndexField = false,
            IncludeResultLevel = false,
            RootElementName = "FeaturedItems",
            RowElementNameFormat = "Item"
        };

    return XmlNodeFactory.Create(xmlReader);      
}