Table per class hierarchy unique constrain on discriminator and subclass properties

Question

Consider the following class hierarchy:

public abstract class Animal {}

public class Dog : Animal
{
    public int DogTagNumber { get; set; }
}

public class Cat : Animal
{
    public int CatTagNumber { get; set; }
}

Note: DogTagNumber and CatTagNumber is purposely placed in the subclasses instead of as TagNumber in Animal class to demonstrate property explicit to each subclass.

The question: Using Fluent NHibernate, is it possible to map unique constrain on class discriminator together with subclasses's explicit properties, like below:

Unique("DOG", DogTagNumber) and also Unique("CAT", CatTagNumber)

The purpose is to ensure the uniqueness of each Dog and Cat with regard to the discriminator in the table on database level.

Thanks in advance.

Solved, see [SO Q1](http://stackoverflow.com/questions/4041365/multiple-unique-keys-in-nhibernate), [SO Q2](http://stackoverflow.com/questions/834565/how-to-create-a-multi-column-index-or-unique-constraint-with-nhibernate) — 1156140, Jan 19 '12 at 06:42

score 0 · Answer 1 · answered Jan 18 '12 at 15:32

0

try this one:

   Map(x => x.Something).UniqueKey("KeyName");
   DiscriminateSubClassesOnColumn("discr_column").UniqueKey("KeyName");

answered Jan 18 '12 at 15:32

mynkow

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I have actually came across that before and that produces Unique("discr_column", DogTagNumber, CatTagNumber) instead of the desired Unique("discr_column", DogTagNumber) and Unique("discr_column", CatTagNumber). – 1156140 Jan 19 '12 at 00:59

Table per class hierarchy unique constrain on discriminator and subclass properties

1 Answers1