Some details on older post about usertype

 1     class StringListUserType : IUserType
 2     {
 3         private const char cStringSeparator = '#';
 4 
 5         #region Equals member
 6 
 7         bool IUserType.Equals(object x, object y)
 8         {
 9             if (x == null || y == null) return false;
10             IList<String> xl = (IList<String>) x;
11             IList<String> yl = (IList<String>) y;
12             if (xl.Count != yl.Count) return false;
13             Boolean retvalue =  xl.Except(yl).Count() == 0;
14             return retvalue;
15         }
16 
17         #endregion
18 
19         #region IUserType Members
20 
21         public object Assemble(object cached, object owner)
22         {
23             return cached;
24         }
25 
26         public object DeepCopy(object value)
27         {
28             IList<String> obj = (IList<String>)value;
29             List<String> retvalue =obj.ToList();
30 
31             return retvalue;
32         }
33 
34         public object Disassemble(object value)
35         {
36             return value;
37         }
38 
39         public int GetHashCode(object x)
40         {
41             return x.GetHashCode();
42         }
43 
44         public bool IsMutable
45         {
46             get { return true; }
47         }
48 
49         public object NullSafeGet(System.Data.IDataReader rs, string[] names, object owner)
50         {
51             List<String> result = new List<String>();
52             Int32 index = rs.GetOrdinal(names[0]);
53             if (rs.IsDBNull(index) || String.IsNullOrEmpty((String) rs[index]))
54                 return result;
55             foreach (String s in ((String)rs[index]).Split(cStringSeparator))
56                 result.Add(s);
57             return result;
58         }
59 
60         public void NullSafeSet(System.Data.IDbCommand cmd, object value, int index)
61         {
62             if (value == null || value == DBNull.Value)
63             {
64                 NHibernateUtil.String.NullSafeSet(cmd, null, index);
65             }
66             IEnumerable<String> stringList = (IEnumerable<String>) value;
67             StringBuilder sb = new StringBuilder();
68             foreach(String s in stringList) {
69                 sb.Append(s);
70                 sb.Append(cStringSeparator);
71             }
72             if (sb.Length > 0) sb.Length--;
73             NHibernateUtil.String.Set(cmd, sb.ToString(), index);
74         }
75 
76         public object Replace(object original, object target, object owner)
77         {
78             return original;
79         }
80 
81         public Type ReturnedType
82         {
83             get { return typeof(IList<String>); }
84         }
85 
86         public NHibernate.SqlTypes.SqlType[] SqlTypes
87         {
88             get { return new SqlType[] { NHibernateUtil.String.SqlType }; }
89         }
90 
91         #endregion
92     }