Ayende @ Rahien

Sebastijan Pistotnik commented on NHibernate -

Wed, 01 Jul 2009 00:27:57 GMT

Ups...sorry for the question...I found it...it seems that you can add as many properties as you need...I just wonder now what would Restrictions.NaturalId() return in this case...

Sebastijan Pistotnik commented on NHibernate -

Wed, 01 Jul 2009 00:16:07 GMT

Scenario: Let us assume that on class User we use soft deletable feature, so there is another property IsDeleted added. To create an unique constraint in a database, we must add additional field to Username and that is for example DateCreated field, since othewise soft deleting will not work properly. Can natural-id be composed of two properties (Username And DateCreated); composite class with equals and hash?

Ayende Rahien commented on NHibernate -

Thu, 25 Jun 2009 12:57:35 GMT

Yes, as I said NH-1852

Carlos Fortes commented on NHibernate -

Thu, 25 Jun 2009 11:29:07 GMT

Uff sorry for the last comment. I was thinking in: class name="AdministrativeFile" table="AdministrativeFiles" id name="Id"> /id> natural-id mutable="false" property name="FileNumber" generator="CustomGeneratorInheritedFromHilo"/ /natural-id or better (use

Carlos Fortes commented on NHibernate -

Thu, 25 Jun 2009 11:24:36 GMT

I was thinking in:

or better (use Natural-id is the real id, but we use other (invented) id ONLY for convenience.

Carlos Fortes commented on NHibernate -

Thu, 25 Jun 2009 10:59:04 GMT

Yes and no. That is the use of generators for any property and for any purpose (not only generate unique id for

Ayende Rahien commented on NHibernate -

Thu, 25 Jun 2009 10:32:28 GMT

You seems to be looking for this: [http://nhjira.koah.net/browse/NH-1852](http://nhjira.koah.net/browse/NH-1852)

Carlos Fortes commented on NHibernate -

Thu, 25 Jun 2009 08:18:04 GMT

Yes, but what if i want use a database sequence in order to obtain the correlative number? I can create a class for that, but i see more more natural use an id generator becouse it use database access and we use nhibernate for that work.

Ayende Rahien commented on NHibernate -

Thu, 25 Jun 2009 07:51:30 GMT

Isn't that why you have field initializer for?

Carlos Fortes commented on NHibernate -

Thu, 25 Jun 2009 07:46:05 GMT

For example, "year/correlativeNumber" like administrative file number. It is an ID that we can calculate like an ID, and it is a natural ID becouse user will see that ID and will use it in the bussines process.

Ayende Rahien commented on NHibernate -

Thu, 25 Jun 2009 07:12:04 GMT

What is the usage scenario you have in mind?

Carlos Fortes commented on NHibernate -

Thu, 25 Jun 2009 07:04:12 GMT

I would like use (custom) id generators with natural-id. It would be posible?

Ayende Rahien commented on NHibernate -

Tue, 23 Jun 2009 19:06:20 GMT

Oh, no, it will do nothing. If you really care about this scenario, you have to manually place a Flush in the middle

Carlos Cubas commented on NHibernate -

Tue, 23 Jun 2009 18:39:11 GMT

I should clarify that the SaveOrUpdate takes a new instance(new User("Carlos")) as follows. SaveOrUpdate(new User("Carlos"));

Carlos Cubas commented on NHibernate -

Tue, 23 Jun 2009 18:37:17 GMT

This mostly has to do with an issue I've deal with in the past. Consider the Entity : User -Id //PK -Name //Natural ID (Unique Constraint on DB) An error will occur if I: Load("Carlos") Delete("Carlos") SaveOrUpdate("Carlos") Flush() As per NHibernate flush documentation, the inserts will happen first, tripping the unique constraint on Name on the already existing row on the table. I was wondering if with the introduction of a feature such as

Ayende Rahien commented on NHibernate -

Tue, 23 Jun 2009 18:17:09 GMT

Scott, No, it will not.

Ayende Rahien commented on NHibernate -

Tue, 23 Jun 2009 18:12:46 GMT

Carlos, I am not following you

Ayende Rahien commented on NHibernate -

Tue, 23 Jun 2009 18:08:27 GMT

Dave, I wouldn't worry about that too much, the only effect it will have is that for the duration of the cache, you'll be able to find the user by both usernames.

Scott White commented on NHibernate -

Tue, 23 Jun 2009 17:24:23 GMT

Will this be used to generate Equals/GetHashCode overrides in the proxies?

Carlos Cubas commented on NHibernate -

Tue, 23 Jun 2009 16:02:37 GMT

I wonder if this feature could be used to *improve* on the flush's insert-update-delete order of operation. Knowing the entity contains a non-mutable natural id gives enough context to know that the flush should do a delete-insert-update instead for this entity.

Dave Harms commented on NHibernate -

Tue, 23 Jun 2009 15:10:16 GMT

Good to know, thanks. Any thoughts on how to handle a situation where the natural id *may* change? For instance, I don't allow my web site users to change their own username, but I will on request change it for them. This doesn't happen often - just a few times per year. Do I just call sessionFactory.evict() after changing the natural id?