Okay, so let's say I have a Person and a Dog class.

- Person can have a Dog, but only one.
- Not all people have a Dog.
- Some Persons have the same Dog (person-> dog = many->one).

In my data schema, this is normalized properly as something like this:

create table Person
(PersonGuid uniqueidentifier not null primary key,
FirstName varchar(50) not null,
LastName varchar(50) not null)

create table Dog
(DogGuid uniqueidentifier not null primary key,
DogName varchar(50) not null)

create table PersonDog
(PersonGuid uniqueidentifier not null references Person(PersonGuid)
DogGuid uniqueidentifier not null references Dog(DogGuid)
)

--Slap a unique composite key on PersonGuid and DogGuid in PersonDog

I do not want to allowable nullable value into Person, with something like this:

(PersonGuid uniqueidentifier not null primary key,
FirstName varchar(50) not null,
LastName varchar(50) not null,
DogGuid uniqueidentifier null references Dog(DogGuid) )

Can anyone advise me on how i'm supposed to go about structuring that relationship? There doesn't seem to be a table attribute in the many->one relationship.

Thanks so much!


--------------------------------------------------------------------------

Hibernate version: urn:nhibernate-mapping-2.2

Mapping documents:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="MyAssembly.Person, MyAssembly" table="Internal.Person">
<id name="Guid" column="PersonGuid" type="Guid">
<generator class="guid"/>
</id>
<property name="FirstName" column="FirstName" type="String" length="50"/>
<property name="LastName" column="LastName" type="String" length="2"/>
</class>
</hibernate-mapping>


<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="MyAssembly.Dog, MyAssembly" table="Internal.Dog">
<id name="Guid" column="DogGuid" type="Guid">
<generator class="guid"/>
</id>
<property name="Name" column="Name" type="String" length="50"/>
<property name="Legs" column="Legs" type="Int32" />
</class>
</hibernate-mapping>

Name and version of the database you are using:
MS SQL Server 2005 sp2

Come on.. I google'd everywhere before I bothered you guys on the forums. I can't be the first person who is adhering to > 3rd normalized form and using NHibernate.

I'm sorry to have to imform you that the 3rd normal form does not require relation tables for one-to-many relationships. Even if it were, I'd be hard pressed to find a better or more obvious candidate for denormalization.

hi mate,

you can find everything in this blog

http://sdesmedt.wordpress.com/?s=NHibernate

good luck!

That's why I said "> 3rd normalized form". Additionally, I tend to denormalize for performance reasons, not to shoe horn my data model into the confines of a data access layer.

To the gentleman that posted the link, thank you very much! I'll be checking it out shortly!