Django: Summing values of records grouped by foreign key
- by Dan0
Hi there
In django, given the following models (slightly simplified), I'm struggling to work out how I would get a view including sums of groups
class Client(models.Model):
api_key = models.CharField(unique=True, max_length=250, primary_key=True)
name = models.CharField(unique=True, max_length=250)
class Purchase(models.Model):
purchase_date = models.DateTimeField()
client = models.ForeignKey(SavedClient, to_field='api_key')
amount_to_invoice = models.FloatField(null=True)
For a given month, I'd like to see e.g.
April 2010
For Each Client that purchased this month:
* CLient: Name
* Total amount of Purchases for this month
* Total cost of purchases for this month
For each Purchase made by client:
* Date
* Amount
* Etc
I've been looking into django annotation, but can't get my head around how to sum values of a field for a particular group over a particular month and send the information to a template as a variable/tag.
Any info would be appreciated
