ForeignKey. How to get data? - django

Question

class Property(models.Model):
title = models.CharField(max_length=255)
class CurrentPrice(models.Model):
current = models.ForeignKey(Current)
prop = models.ForeignKey(Property)
price = models.DecimalField(max_digits=5, decimal_places=2)
class Current(models.Model):
name = models.CharField(max_length=20)
views.py:
...
p = Property.objects.all()
return render_to_response('index.html',{'p':p},context_instance=RequestContext(request))
How to get price of Property and display it in my template?
template:
{% for item in p %}
{{ item.title }}
{{ item.price }} # ???
{% endfor %}

Answer 1

I'm not sure what is your purpose/design of models, which doesn't look appropriate from what you have shown.
You will have many CurrentPrice per Property object, so in template you can do is
{% for item in p %}
{{ item.title }}
{% for cp in item.currentprice_set.all %}
{{ cp.price }}
{% endfor %}
{% endfor %}

Answer 2

If Property can have multiple CurrentPrice objects (what is by default):
{% for item in p %}
{{ item.title }}
{% for current_price in item.currentprice_set.all %}
{{ current_price.price }}
{% endofor %}
{% endfor %}
If only one (but in that case it is better to use o2o field instead of the FK fiel else it is up on you to prevent multiple CurrentPrice records pointing to the same Property):
{% for item in p %}
{{ item.title }}
{{ item.currentprice_set.get.price }}
{% endfor %}

Answer 3

I think what you're trying to do is something like that below.
class Property(models.Model):
title = models.CharField(max_length=255)
#property
def current_price(self):
# The current price is the last price that was given.
if self.pricing_history.count() > 0:
return self.pricing_history.order_by('-when')[0].amount
return None
class Price(models.Model):
prop = models.ForeignKey(Property, related_name='pricing_history')
amount = models.DecimalField(max_digits=5, decimal_places=2)
when = models.DateTimeField(auto_now_add=True)
example in template:
{% for item in p %}
{{ item.title }}
{{ item.current_price }}
{% endfor %}