On Wed, Sep 8, 2010 at 12:51 AM, Don <[email protected]> wrote: > I need to create a query that aggregates values by the year of a date > field. I have not been able to discover a way to do this yet, perhaps > someone can help. I can issue the following raw query, which gives the > results I want: > > cursor.execute("""SELECT year(oac_date) as year, month(oac_date) as > month, sum(oac_actualconsumption) as consumption > FROM actualconsumption > WHERE oac_object = %s AND oac_commodity = %s AND > year(oac_date) = %s > GROUP BY year(oac_date), month(oac_date) > ORDER BY month(oac_date)""", [object_id, commodity, year]) > > Where oac_object is the pk for the table. > > This summarizes the oac_actualconsumption by year. Does anyone have an > idea how to do this without resorting to a raw query? I have not been > able to get the aggregates to work over parts of a date field in the > database, only on the whole field.
This is a known limitation of the current aggregates. It's something I'd like to address, since "aggregate X's that occurred on Monday" is a pretty common pattern. This is logged as ticket #10302. In the meantime, the discussion on the ticket contains an extra()-based workaround that can be used in some circumstances. Yours, Russ Magee %-) -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
