SQL 2008 HierarchyID support in NHibernate

Question

Searched various NHibernate lists and haven\'t come up with a definitive answer. The SQL2008 dialect doesn\'t appear to have support for the HierarchyID data type - new dat

Answer 1

I've given Needles' answer a test run. It's a very good answer but there are some changes needed to make it function (at least in .NET 4). Here's what I've come up with for my project:

Update: the following code can be download over at GitHub and will be updated there. NHiberntate.HierarchyId.UserType

SqlHierarchyId IUserType

namespace NHibernate.UserTypes
{
    using SqlTypes;
    using System;
    using System.Data;
    using System.Data.SqlTypes;
    using Microsoft.SqlServer.Types;

    public class HierarchyId : IUserType
    {
        #region Properties

        public SqlType[] SqlTypes
        {
            get { return new[] { NHibernateUtil.String.SqlType }; }
        }

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

        public bool IsMutable
        {
            get { return true; }
        }

        #endregion Properties

        #region Methods

        new public bool Equals(object x, object y)
        {
            if (ReferenceEquals(x, y)) return true;
            if (x == null || y == null) return false;

            return x.Equals(y);
        }

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

        public object NullSafeGet(IDataReader rs, string[] names, object owner)
        {
            object prop1 = NHibernateUtil.String.NullSafeGet(rs, names[0]);

            if (prop1 == null) return null;

            return SqlHierarchyId.Parse(new SqlString(prop1.ToString()));
        }

        public void NullSafeSet(IDbCommand cmd, object value, int index)
        {
            if (value == null)
                ((IDataParameter)cmd.Parameters[index]).Value = DBNull.Value;

            else if (value is SqlHierarchyId)
                ((IDataParameter)cmd.Parameters[index]).Value = ((SqlHierarchyId)value).ToString();
        }

        public object DeepCopy(object value)
        {
            if (value == null) return null;

            return SqlHierarchyId.Parse(((SqlHierarchyId)value).ToString());
        }

        public object Replace(object original, object target, object owner)
        {
            return DeepCopy(original);
        }

        public object Assemble(object cached, object owner)
        {
            return DeepCopy(cached);
        }

        public object Disassemble(object value)
        {
            return DeepCopy(value);
        }

        #endregion Methods
    }
}

Mapping

    

        
        ...

    

Object with HierarchyId

namespace NHibernate.Map
{
    using Microsoft.SqlServer.Types;

    public class OrganizationUnit
    {
        #region Fields

        private SqlHierarchyId _hierarchyId;
        ...

        #endregion Fields

        #region Properties

        public virtual SqlHierarchyId HierarchyId
        {
            get { return _hierarchyId; }
            set { _hierarchyId = value; }
        }
        ...

        #endregion Properties
    }
}