I'm just curious if there is a mapping work around to problem described below.

Given the following schema:

Table: List
PK - ListName
...

Table: Attribute
PK - AttributeName
...

Table: ListAtt
PK, FK1 - ListName
PK, FK2 - AttributeName

And the following mapping:


I run into the following exception:
failed: System.Xml.XmlException : 'column' is a duplicate attribute name.

I have also tried the following mapping for the same AppList class mapping:

With it I run into the following exception:
failed: NHibernate.MappingException : The element 'urn:nhibernate-mapping-2.0:map' has incomplete content. Expected 'urn:nhibernate-mapping-2.0:element urn:nhibernate-mapping-2.0:one-to-many urn:nhibernate-mapping-2.0:many-to-many urn:nhibernate-mapping-2.0:composite-element urn:nhibernate-mapping-2.0:many-to-any'.

I know the solution may be to add an index column to the ListAtt table, but it seems like this is a very common implementation without having to do so. I would think that there should be, or potentially is, a way to implement an IDictionary collection with the <map> element using the foreign key as both the relationship mapping and the index mapping. In my case implementing an index column would introduce redundant data in the table. Please advise. Thanks in advance for any help.

nathan

You have column attribute specified twice in your first extract, hence the error.

Sorry for that.

The first snippet should actually be...


And the exception:
failed: NHibernate.MappingException : Repeated column in mapping for collection: ApplicationLists.ORM.List.Attributes column: AttributeName