First off, I'm using NHibernate 1.2.0 and MSSQL with a schema that cannot be changed.

I have a class called RoleAssignment, who's key is a composite consisting of a User object and a Role object. This maps to a shared primary key in the database.

The RoleAssignment class has a list of CompositeConstraint objects. That class has a Guid primary key, but I reference the rows by LoginId (user's PK) and RoleId (role's PK)

I'm not exactly sure how to map this. My bag looks like this:



but I'm not sure how I specify that the RoleId and LoginId columns come from the classes that make up the composite key of this class.

Any help would be greatly appreciated.

Should I change the composite-key to containt key columns, rather than <key-many-to-one>s? Or will NHibernate know to map the primary key of the composite key classes and use those for the bag reference above?

Any help is greatly appreciated.

I did some more research, and I'm getting a LazyInitialize exception even though the collection isn't lazy. This happens whether I have <key-property> or <key-many-to-one> for the <composite-id> element.

I was able to work around the problem by adding a surrogate key to the database and mapping a standard <id> to that, but I don't want to introduce schema changes, as this is a legacy system in use.

Why would I get a "Failed to lazily initialize a collection - no session" error when the collection isn't lazy? The only thing is that both classes have composite keys.

Any help here would be greatly appreciated. Thanks.

You didn't specify lazy="false" for your bag

Yes you're right, but I get the same results even if I do specify it. Isn't Lazy=false the default?

The documentation says it is, but I've found explicitly declaring it forces lazy loading not to happen. Are you serializing your containing object?

No. I have a test that saves the parent object to a database (with child objects).

It then reloads it from the database and checks if the child objects got loaded as well. The error happens at that last step, when accessing the collection.

According to http://forum.hibernate.org/viewtopic.php?t=960004,
starting with 1.2.0Alpha1, the default is lazy=true

Gert

I'm using 1.2.0, so I think it's ok.

Besides I've been saving/loading collections the same way (not specifying lazy) and it works for all of my other mappings.

Good to know that lazy=true is the new default.

update: I decided to move forward with this issue and add a surrogate key to the 2 tables in question, and now it's working, but this is on my development database. Migrating these changes to production is going to be a pain to explain and carry out.

Can anyone find a reason why this isn't working? Am I mapping it correctly?

Hi,

I think I've run into your same problem:
http://forum.hibernate.org/viewtopic.php?t=964255

From what i've found so far looks like a restriction. You can make a 1:many association if the child it's not related using the Primary Key.

Sebastian