NHibernate child object's ID problem.

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NHibernate child object's ID problem.

When I retrieve a Parent-object, the Child-object's ID is not always predictable. For example, sometimes it is set with 0 (zero), sometimes the actual value and sometimes -1.

Why?

How can I solve this problem?

For code and mapping-files plz see this older question from me.

Your Teacher and TeacherDetail are setup different.

One is a many-to-one and the other is a one-to-one.

bleevo 2010-07-18 01:56:34

+1 A:

Considering that SQL Server's default identity setting will never set a value of 0 or -1 something is fishy.

Also, since the TeacherDetail is actually a supplementary/sibbling entity of Teacher why the additional ID for TeacherDetail? You can map a Primary Foreign Key in nhibernate

Jaguar 2010-07-20 17:27:52

I would say that your premise is incorrect.

A single teacher only has a single detail, and therefore nothing is many-to-one. It's all just a property, as in a teacher has a property of TeacherDetail.

Either way, there is no way that TeacherDetailsMapping has a many-to-one...two teachers will never share the same details.

Fix the improper mapping and your issue, a result of bad mapping, will disappear.

The Mirage 2010-07-21 12:53:52

I don't know whether you are aware or not, one-to-one relationship from the patent side is mapped as many-to-one with unique set to true. See this: http://nhforge.org/wikis/howtonh/lazy-loaded-one-to-one-with-nhibernate.aspx

JMSA 2010-07-22 13:47:01

perhaps being clear about what you are trying to do would be helpful. That is a workaround 'trick' not a standard practice.Not sure what to tell you, I'm pretty sure you can map it "better".

The Mirage 2010-07-22 17:35:37

@Mirage this IS the way to map one-to-ones; one side maps as a many-to-one

Jaguar 2010-07-23 06:07:12

ansaurus

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NHibernate child object's ID problem.

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