An NHibernate Mutable Type for XML in SQL Server.

XmlType.cs

    [Serializable]
    public class XmlType<T> : MutableType
        where T : class
    {
        public XmlType()
            : base(new XmlSqlType())
        {
        }

        public override string Name
        {
            get { return "XmlTypeOfT"; }
        }

        public override Type ReturnedClass
        {
            get { return typeof(T); }
        }

        public override void Set(IDbCommand cmd, object value, int index)
        {
            var valueTyped = value as T;
            Set(cmd, valueTyped, index);
        }

        public void Set(IDbCommand cmd, T value, int index)
        {
            ((IDataParameter)cmd.Parameters[index]).Value = XmlUtil.ToXml(value);
        }

        public override object Get(IDataReader rs, int index)
        {
            return rs.IsDBNull(index) ? null : FromStringValue((string)rs[index]);
        }

        public override object Get(IDataReader rs, string name)
        {
            return Get(rs, rs.GetOrdinal(name));
        }

        public override string ToString(object val)
        {
            var valueTyped = val as T;
            return valueTyped != null ? XmlUtil.ToXml(valueTyped) : null;
        }

        public override object FromStringValue(string xml)
        {
            return xml != null ? XmlUtil.FromXml<T>(xml) : null;
        }

        public override object DeepCopyNotNull(object value)
        {
            var valueAsXmlString = ToString(value);
            return FromStringValue(valueAsXmlString);
        }

        public override bool IsEqual(object x, object y)
        {
            if (x == null && y == null)
            {
                return true;
            }

            if (x == null || y == null)
            {
                return false;
            }

            return ToString(x) == ToString(y);
        }
    }