django-mosql 0.5

Why?

How do I use this thing?

(Examples in this section are inspired by this blog post by Baron Schwartz.)

Let’s say you have the following model:

class Fruit(models.Model):
    kind = models.CharField(max_length=10)
    variety = models.CharField(max_length=10)
    price = models.FloatField()

Then you only need to provide a MoManager as one of its model managers. Add djangomosql to your INSTALLED_APPS, and modify the code like this:

from djangomosql.models import MoManager

class Fruit(models.Model):
    kind = models.CharField(max_length=10)
    variety = models.CharField(max_length=10)
    price = models.FloatField()

    objects = MoManager()

And you’ll be able to generate queries like this:

from djangomosql.functions import Min

Fruit.objects.select((Min('price'), 'minprice')).group_by('kind').order_by('-kind')

Which is roughly equivalent to

SELECT fruit.*, MIN(price) as minprice FROM fruit GROUP BY kind ORDER BY kind DESC

Of course, this won’t be of much use if we can only do things Django’s ORM can. With Django MoSQL, you can achieve many funky things, like:

m = Fruit.objects
inner = m.select((Min('price'), 'minprice')).group_by('kind')
p = m.select().as_('f').order_by('f.kind').join(
    inner, 'x', on={'f.kind': 'x.kind', 'f.price': 'x.minprice'}
)

Which can be translated into (again, roughly):

SELECT f.* FROM fruit AS f INNER JOIN (
    SELECT *, MIN(price) as minprice FROM fruit GROUP BY kind
) AS x ON f.kind = x.kind AND f.price = x.minprice

And best of all, you get all the escaping and ORM mapping for free!

LICENSE

BSD 3-cluse license. See the content of file LICENSE.

Developing

To run tests, run python manage.py test inside the test project. You will need django-nose as well as the dependencies.