On Dec 25, 2011, at 7:36 AM, VDK wrote:
> I have the following piece of code:
>
> class ContributieNotas(object):
>
> class Admin(EntityAdmin):
> verbose_name = 'Contributie notas'
> verbose_name_plural = 'Contributienota\'s'
> list_display = ['id', 'achternaam', 'tussenvoegsel',
> 'voorletters', 'adres',
> 'postcode', 'woonplaats','omschrijving',
> 'tariefbedrag', 'adresenpc']
>
> def setup_views():
>
> q = select([model.Leden.id, model.Leden.achternaam,
> model.Leden.tussenvoegsel, model.Leden.voorletters,
> model.Leden.adres, model.Leden.postcode,
> model.Leden.woonplaats, model.Tarieven.omschrijving,
> model.Tarieven.tariefbedrag,
> model.Leden.adresenpc],
> whereclause =
> and_(model.Leden.lidsoort_id.in_([1,2]),
> model.Tarieven.id == model.Leden.lidsoort_id),
> order_by = (model.Leden.achternaam))
>
> q = q.alias('contributie_alle_leden')
>
> mapper(ContributieNotas, q)
First off is definitely analyze the issue in terms of SQL using echo=True.
There's no default ORDER BY in modern SQLAlchemy so the primary key ordering is
likely just the insert ordering of the table. This is not directly linked to
the primary key except that surrogate integer primary keys are typically
assigned sequentially as rows are inserted. Second, the ORDER BY here will
be rendered inside an aliased select, "SELECT * FROM (SELECT * FROM ... ORDER
BY ...) as contribute_alle_leden WHERE <criterion>". Generally this will
maintain that ordering but not necessarily, if the selectable is part of a
bigger context that again changes how the database merges rows into the final
result set. So for the ordering of the final result, the ORDER BY should be
on the outside.
mapper() offers an option called order_by which will instruct the Query object
to place this as the default ORDER BY in the absence of other orderings. It
must be in terms of the mapped selectable, here the q.alias():
mapper(ContNot, q.c.achternaam)
>
> one of them is putting the order by clause in the mapper but without
> result.
so if you've tried this then something else is off, and watching the generated
SQL will begin to describe what's actually happening.
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