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Foreign key part of unique constraint or primary key

Original Post

Fionn

24 May, 2010 09:05 PM via web

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Hi,

is it possible to include the foreign-key which is created for an many-to-one mapping in an index/unique constraint with a fluent mapping?

I have something like the following:

class Document
{
    Guid Id;
    public virtual IList<DocumentRevision> Revisions { get; private set; }
}

class DocumentRevision
{
    Guid document_id; 
    int revision;
}

Is it possible to have a primary key for the document revision table which consists of document_id and revision, since a given revision must only exist a single time for each document. Also a combined index should be beneficial because most querys would be like give me the latest revision of a given document.

But I haven't found a way to create a mapping for this.

Thanks

1. 2 Posted by rkevinstout on 25 May, 2010 08:58 PM

   

   This can be accomplished by using a CompositeId. For example:

       class DocumentRevisionMap : ClassMap<DocumentRevision>
       {
           public DocumentRevisionMap()
           {
               CompositeId()
                   .KeyProperty(x => x.revision)
                   .KeyReference(x => x.document_id);  
           }
       }
   

   Good luck,

   Kevin Stout

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2. 3 Posted by Fionn on 25 May, 2010 09:47 PM

   

   Would it also be possible if not specifying the foreign key as Guid but as class reference, like with this classes:

   class Document
   {
       Guid Id;
       public virtual IList<DocumentRevision> Revisions { get; private set; }
   }
   
   class DocumentRevision
   {
       Document ParentDocument;
       int Revision;
   }
   

   Thanks

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3. 4 Posted by rkevinstout on 25 May, 2010 10:42 PM

   

   Yes, you are correct.
   

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