Hibernate version: 1.2.1

Mapping documents:

Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:attempt to delete null

Name and version of the database you are using:sql server 2005

The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:


I have two class: President, Nation. There are one-to-one relation between them. The Nation is the main class, it has property Persident. The Persident has property Nation, and it's key is generated by the Nation property.

I have a Nation object, and it's Persident is null. When i delete the Nation, it successed, but the delete of Persident is wait to do. So when i access the database next time, it will delete the Persident though the property is null, and throw a exception said: attemped to delete null.

I see the scheam, the one to one relation mapping doesn't has "not-null" attribute as many-to-one relation mapping.

How can deal with this problem?

My mother tongue is not English, I'm sorry.

A one-to-one association does not support nulls at either end of the association. If a Nation can exist without a President, then you have to use a many-to-one association.