NHibernate.Custom.XmlType.cs

/* 
 * UserType allowing easy saving of NHIbernate XmlDocument property.
 *
 * Example
 * =======
 * 
 * //Message.cs - Example class with a XmlDocument
 * public class Message
 * {
 *    public XmlDocument Body{get;set;}
 * }
 *
 * //Message.hbm.xml - The mapping
 * <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
 *   <class name="Message">
 *     <property name="Body" type="NHibernate.Custom.XmlType, NHibernate.Custom" />
 *   </class>
 * </hibernate-mapping>
 *
 * History
 * ======= 
 * - This code was found online somewhere, sorry, I can't remember where :-( 
 * - I've tweaked it a little to work with 2nd level cache and NHibernate 2.1.x. 
 * - Tobin Harris
 */
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Text;
using System.Xml;
using NHibernate.SqlTypes;
using NHibernate.UserTypes;

namespace NHibernate.Custom
{
	public class XmlType : IUserType
	{
	    public new bool Equals(object x, object y)
	    {
	        if (x == null || y == null)
	            return false;

	        var xdoc_x = (XmlDocument) x;
	        var xdoc_y = (XmlDocument) y;
	        return xdoc_y.OuterXml == xdoc_x.OuterXml;
	    }

	    public int GetHashCode(object x)
	    {
	        return x.GetHashCode();
	    }


	    public object NullSafeGet(IDataReader rs, string[] names, object owner)
	    {
	        if (names.Length != 1)
	            throw new InvalidOperationException("names array has more than one element. can't handle this!");
        
	        var document = new XmlDocument();
        
	        var val = rs[names[0]] as string;
        
	        if (val != null)
	        {
	            document.LoadXml(val);
	            return document;
	        }

	        return null;
	    }

	    public void NullSafeSet(IDbCommand cmd, object value, int index)
	    {
	        var parameter = (DbParameter )cmd.Parameters[index];
        
	        if(value == null)
	        {
	            parameter.Value = DBNull.Value;
	            return;
	        }
        
	        parameter.Value = ((XmlDocument) value).OuterXml;
	    }

	    public object DeepCopy(object value)
	    {
        
	        var toCopy = value as XmlDocument;
        
	        if(toCopy==null)
	            return null;

	        var copy = new XmlDocument();
	        copy.LoadXml(toCopy.OuterXml);
	        return copy;
	    }

	    public object Replace(object original, object target, object owner)
	    {
	        throw new NotImplementedException();
	    }

	    public object Assemble(object cached, object owner)
	    {
	        var str = cached as string;
	        if (str != null)
	        {
	            var doc = new XmlDocument();
	            doc.LoadXml(str);
	            return doc;
	        }
	        else
	        {
	            return null;
	        }

	    }

	    public object Disassemble(object value)
	    {
	        var val = value as XmlDocument;
	        if(val != null)
	        {
	            return val.OuterXml;
	        }
	        else
	        {
	            return null;
	        }
	    }

	    public SqlType[] SqlTypes
	    {
	        get 
	        {
	            return new SqlType[] { new SqlXmlStringType() };
	        }
	    }

	    public Type ReturnedType
	    {
	        get { return typeof(XmlDocument); }
	    }

	    public bool IsMutable
	    {
	        get { return true; }
	    }
	}

	public class SqlXmlType : SqlType
	{
	    public SqlXmlType() : base(DbType.Xml)
	    {
	    }
	}

	public class SqlXmlStringType : SqlType
	{
	    public SqlXmlStringType()
	        : base(DbType.String, 4000)
	    {
	    }     
	}

}

Hi,
I need your help on this issue. i am trying NHibarnate mapping to DB2 table which has a column with datatype "XML". I followes the ame approach but getting error "Unknown SQL type - -370". on detail stack trace i got eoor starting from "NullSafeGet(IDataReader rs, String[] names, Object owner)" function. on "var val = rs[names[0]] as string;" line.

can anyone help me out please....