Let me start with this... Suppose you have a class, Customer, and a map
for it:
public class CustomerMap : ClassMap<Customer>
{
public CustomerMap()
{
Table("tblCustomers");
Id(x => x.Id, "CustomerID")
.GeneratedBy.Identity()
.CustomType<BaseIdUserType<CustomerId>>()
.GeneratedBy.Identity()
.UnsavedValue(0);
CustomerId just extends BaseId which wraps an int. And BaseIdUserType<TId>
is a custom NHibernate UserType for these wrapped int's:
internal static class BaseIdUserTypeConstants
{
internal static readonly Type[] ConstructorTypes = new[] {typeof
(int)};
internal static readonly SqlType[] SqlTypes = new[]
{NHibernateUtil.Int32.SqlType};
}
/// <summary>
/// Custom NHibernate user type for subclasses of <see cref="BaseId"/>.
///
/// Based on
http://darrell.mozingo.net/2009/02/10/generic-nhibernate-user-type-base-class/
/// </summary>
/// <typeparam name="TId">The type of the ID class</typeparam>
public class BaseIdUserType<TId> : IEnhancedUserType
where TId : BaseId
{
public new bool Equals(object x, object y)
{
return object.Equals(x, y);
}
public int GetHashCode(object x)
{
if(x == null) return 0;
return x.GetHashCode();
}
public object NullSafeGet(IDataReader rs, string[] names, object
owner)
{
object obj = NHibernateUtil.Int32.NullSafeGet(rs, names[0]);
if ( obj==null ) return null;
int idValue = (int) obj;
TId id = ToId(idValue);
return id;
}
private TId ToId(int idValue)
{
return (TId)Constructor.Invoke(new object[] {idValue});
}
private ConstructorInfo Constructor
{
get
{
if (_constructor == null)
{
_constructor = typeof
(TId).GetConstructor(BaseIdUserTypeConstants.ConstructorTypes);
if(_constructor == null) throw new
SystemException(string.Format("{0} does not have a constructor of the form
{0}(int)", typeof(TId).Name));
}
return _constructor;
}
}
private ConstructorInfo _constructor;
public void NullSafeSet(IDbCommand cmd, object value, int index)
{
if (value == null)
{
((IDataParameter)cmd.Parameters[index]).Value =
DBNull.Value;
}
else
{
TId id = (TId)value;
((IDataParameter)cmd.Parameters[index]).Value = id.Value;
}
}
public object DeepCopy(object value)
{
return value; // Because BaseId's are immutable, the same
instance can stand in for a "copy"
}
public object Replace(object original, object target, object owner)
{
return original; // Becuase BaseId's are immutable, we can
return the first value (the original value), as per the IUserType docs
}
public object Assemble(object cached, object owner)
{
return DeepCopy(cached);
}
public object Disassemble(object value)
{
return DeepCopy(value);
}
public SqlType[] SqlTypes { get { return
BaseIdUserTypeConstants.SqlTypes; } }
public Type ReturnedType { get { return typeof (TId); } }
public bool IsMutable { get { return false; } }
public override string ToString()
{
return string.Format("BasedIdUserType[{0}]", typeof (TId).Name);
}
public object FromXMLString(string xml)
{
return ToId(Convert.ToInt32(xml));
}
public string ObjectToSQLString(object value)
{
return Convert.ToString(((TId)value).Value);
}
public string ToXMLString(object value)
{
return Convert.ToString(((TId)value).Value);
}
}
At runtime, this produces an exception:
System.InvalidOperationException: Identity type must be integral (int,
long, uint, ulong)
at FluentNHibernate.Mapping.GeneratorBuilder.EnsureIntegralIdenityType()
at FluentNHibernate.Mapping.GeneratorBuilder.Identity()
at
FluentNHibernate.Mapping.IdentityGenerationStrategyBuilder`1.Identity()
at MySys.Customers.CustomerMap..ctor()
But this in fact is a false constraint! If I swap the GeneratedBy with
this, it works absolutely fine (I have it in production like this):
.GeneratedBy.Custom("identity")
So I can bypass the fluent methods to explicitly put what the fluent method
would have used, were it not for the over-zealous guard
in GeneratorBuilder.Identity().
On Wednesday, October 29, 2014 5:58:04 AM UTC-4, Gleb Chermennov wrote:
>
> Unfortunately, I didn't - got swamped with preparing pre-release and other
> things. But that doesn't mean I'm giving up.
> Can you provide full code sample that reproduces the problem?
>
> вторник, 28 октября 2014 г., 21:51:45 UTC+4 пользователь Trinition написал:
>>
>> Did you ever get a chance to investigate this?
>>
>> On Saturday, July 12, 2014 4:18:34 PM UTC-4, Gleb Chermennov wrote:
>>>
>>> Let me investigate this and I'll come back to you. Sorry I haven't
>>> looked into that before.
>>>
>>> суббота, 12 июля 2014 г., 3:38:08 UTC+4 пользователь Trinition написал:
>>>>
>>>> I opened an issue in GitHub
>>>> <https://github.com/jagregory/fluent-nhibernate/issues/230> about
>>>> this, but it's been idle. Maybe it's because I'm doing something wrong,
>>>> so
>>>> I wanted to check here.
>>>>
>>>> Basically, I'm using a special wrapper class around an int for some of
>>>> my entity IDs. The values are still generated by IDENTITY in the
>>>> database,
>>>> but the properties in the classes aren't just ints. I've base a custom
>>>> UserType for it so I could try to fluently map like this:
>>>>
>>>> Id(x => x.Id)
>>>> .GeneratedBy.Identity()
>>>> .CustomType<BaseIdUserType<FooId>>()
>>>> .UnsavedValue(0);
>>>>
>>>> Fluent NHibernate throws the exception from
>>>> EnsureIntegralIdenityType(). However, if I cheat and work-around Fluent
>>>> NHibernate's restriction, everything works just fine:
>>>>
>>>> Id(x => x.Id)
>>>> .GeneratedBy.Custom("identity")
>>>> .CustomType<BaseIdUserType<FooId>>()
>>>> .UnsavedValue(0);
>>>>
>>>> Is there some other way to get an Custom UserType to work with the
>>>> standard .Identity() generator?
>>>>
>>>
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