Re: [SQLObject] Filtering selections via foreign keys

Hi!

On Wed, Feb 16, 2011 at 02:20:33PM +0800, Jason Heeris wrote:
> I'm trying to filter a selection from one table by looking up a
> referenced value in another table. An example is probably the easiest
> explanation:
> 
> ----
> class DocumentType (SQLObject) :
>     """ What type the document is assigned to.
>     """
>     dbType = StringCol()
> 
> class Document (SQLObject) :
>     """ Location of stored documents
>     """
>     dbPath = StringCol()
>     dbDocumentType = ForeignKey('DocumentType')
> 
> def DocumentSearch(text, type=None):
> 
>     # initial query with text
>     docs = dbase.dbase.SVNDocument.select(...)
> 
>     if type:
>         docs.filter(...)
> 
>     return list(docs)
> ----
> 
> The "docs.filter(...): is where I want to allow only those Documents
> whose dbDocumentType refers to the DocumentType with dbType == type. I
> know this must be simple, but it's been a while since I used SQLObject
> and I just can't see it.

   If SVNDocument is actually Document in this example, and type to
filter must be compared equal to DocumentType.dbType, then filter
should be something like this:

    docs.filter(
        (Document.q.dbDocumentTypeID==DocumentType.q.id) &
        (DocumentType.q.dbType==type)
    )

HTH,
Oleg.
-- 
     Oleg Broytman            http://phdru.name/            ph...@ph...
           Programmers don't die, they just GOSUB without RETURN.