I have two querysets. My first Queryset (services) has all of my service objects. My second Queryset (rating_values) has all of my rating values, where each index corresponds to the index in the services Queryset. For example services[1] corresponds with rating_values[1].
How do I loop through these two queries in an html page in django so so that I can display the service name along with the corresponding rating value?
To be clear, services contains service objects and rating_values contains decimal values. I pass the variables like this:
return render_to_response('services/display_services.html', {'user': request.user, 'services':services, 'rating_values': rating_values })
I would like to do something like this:
{% for service in services %}
<p> {{service.service_name}} : {{ corresponding rating_value}} </p>
Edit
Here is my Service model:
class Service(models.Model):
user_id= models.IntegerField(default=1)
service_name = models.CharField(max_length=100)
address = models.CharField(max_length=200)
def __str__(self): # __unicode__ on Python 2
return self.service_name
Here is my Rating Model:
class Rating(models.Model):
service_id= models.IntegerField(default=1)
service_name= models.CharField(max_length=200)
number_of_ratings = models.IntegerField()
total_rating_value = models.IntegerField()
rating_average = models.FloatField()
def __str__(self): # __unicode__ on Python 2
return self.service_name
Just to answer the original question as well.
If you for some reason don't want a database relation between the models, you could convert the querysets to lists and zip them in the view, turning the querysets to a list of tuples.
view:
return render_to_response(
'services/display_services.html',
context_instance={
'user': request.user,
'services_and_ratings': zip(
services.all(),
rating_values.all()
)
}
)
template:
{% for service, rating in services_and_ratings %}
<p> {{ service.service_name }} : {{ rating.rating_average }} </p>
You can establish the relationship right in the model.
class Rating(models.Model):
service= models.OneToOneField(Service, primary_key=True)
service_name= models.CharField(max_length=200)
number_of_ratings = models.IntegerField()
total_rating_value = models.IntegerField()
rating_average = models.FloatField()
....
You can then pass services and get the corresponding ratings..
{% for service in services %}
<p> {{service.service_name}} : {{ service.rating.rating_average }} </p>
Related
I have two models interrelated items and broken :
class Items(models.Model):
id = models.AutoField(primary_key=True)
item_name = models.CharField(max_length=50, blank=False)
item_price = models.IntegerField(blank=True)
item_quantity_received = models.IntegerField(blank=False)
item_quantity_available = models.IntegerField(blank=True)
item_purchased_date = models.DateField(auto_now_add=True, blank=False)
item_units = models.CharField(max_length=50, blank=False)
def __str__(self):
return self.item_name
class Broken(models.Model):
item = models.ForeignKey(Items, default=1, on_delete=models.CASCADE)
item_quantity_broken = models.IntegerField(blank=True)
item_broken_date = models.DateField(auto_now_add=True, blank=False)
item_is_broken = models.BooleanField(default=True)
date_repaired = models.DateField(auto_now=True, blank=True)
def __str__(self):
return self.item.item_name
I wrote this view function to retrieve data to a table into a template:
def broken_items(request):
br = Broken.objects.select_related('item').all()
print(br.values_list())
context = {
'title': 'broken',
'items': br,
}
return render(request, 'store/broken.html', context)
this is the executing query:
SELECT "store_broken"."id",
"store_broken"."item_id",
"store_broken"."item_quantity_broken",
"store_broken"."item_broken_date",
"store_broken"."item_is_broken",
"store_broken"."date_repaired",
"store_items"."id",
"store_items"."item_name",
"store_items"."item_price",
"store_items"."item_quantity_received",
"store_items"."item_quantity_available",
"store_items"."item_purchased_date",
"store_items"."item_units"
FROM "store_broken"
INNER JOIN "store_items"
ON ("store_broken"."item_id" = "store_items"."id")
looks like it gives me all the fields I want. In debugger it shows data from both tables,
so I wrote for loop in template,
{% for item in items %}
<tr>
<td>{{item.id}}</td>
<td>{{item.item_id}}</td>
<td>{{item.item_quantity_broken}}</td>
<td>{{item.item_broken_date}}</td>
<td>{{item.item_is_broken}}</td>
<td>{{item.date_repaired}}</td>
<td>{{item.item_name }}</td>
<td>{{item.item_item_quantity_received}}</td>
<td>{{item.item_quantity_available}}</td>
<td>{{item.item_purchased_date}}</td>
<td>{{item.items_item_units}}</td>
</tr>
{% endfor %}
The thing is this loop only gives me data from broken table only. I can't see data from Items table.
can someone help me to find the reason why other details are not showing?
Your items query is of Broken objects. So in order to access the Items values you need to change your table. For better understanding change your view like this:
brokens = Broken.objects.select_related('item').all()
context = {
'title': 'broken',
'brokens ': brokens,
}
and then your table:
{% for broken in brokens %}
<tr>
<td>{{broken.id}}</td>
<td>{{broken.item.pk}}</td> # This is the item id
<td>{{broken.item_quantity_broken}}</td>
<td>{{broken.item_broken_date}}</td>
<td>{{broken.item_is_broken}}</td>
<td>{{broken.date_repaired}}</td>
<td>{{broken.item.item_name}}</td>
<td>{{broken.item.item_quantity_received }}</td>
<td>{{broken.item.item_quantity_available}}</td>
<td>{{broken.item.item_purchased_date}}</td>
<td>{{broken.item.items_item_units}}</td>
</tr>
{% endfor %}
you loop over a List of Broken objects
to access the related item objects
item.item.item_name
I'm trying create a table with 2 columns:
1) Collections and 2) Qualified Sales.
Like the image above.
Each book count the own qualified_sales.
The Qualified sales(column in the table) must sum all qualified_sales of all books of each collection.
models.py
class Publishing_company(models.Model):
title = models.CharField(max_length=50)
class Collection(models.Model):
publishing_company = models.ForeignKey(Publishing_company, on_delete=models.CASCADE)
class Book(models.Model):
publishing_company = models.ForeignKey(Publishing_company, on_delete=models.CASCADE)
class Sale(models.Model):
book = models.ForeignKey(Book, on_delete=models.CASCADE)
qualified_sale = models.IntegerField(default=0)
views.py
def qlf_sales(request):
book = Collection.objects.filter(user=request.user)
qualified_sum = Sale.objects.filter(user=request.user, book__publishing_company__collection__in=book).aggregate(Sum('qualified_sale'))['qualified_sale__sum'] or 0
context = {'qualified_sum': qualified_sum}
return render(request, 'template.html', context)
template.html
{% for collection in collections %}
<tr>
<td>{{collection}}</td>
<td>{{qualified_sum}}%</td>
</tr>
{% endfor %}
But this code not work. Dont appear any debug error, but in the all fields in the Qualified Sales' column appear the same value: the sum of all qualified_sales of all sales of all book.
why didn't separate by collection?
If anyone can help me. Please i go a lot grateful.
I have 2 ArrayField lists and I want to join them using the zip method so I can Iterate through two lists in Django my django templates. But the output is treating each as array as seperate lists.
my model
class programas(models.Model):
title = models.CharField(unique=True, max_length=250)
script = ArrayField(models.CharField(max_length=8000, blank=True))
created_on = models.DateTimeField()
show_date = models.CharField(max_length=300, blank=True, null=True)
script_eng = ArrayField(models.CharField(max_length=8000, blank=True))
description = models.CharField(max_length=2000, blank=True, null=True)
description_eng = models.CharField(max_length=2000, blank=True, null=True)
url = models.CharField(max_length=200, blank=True, null=True)
show_id = models.IntegerField(primary_key=True)
id = models.IntegerField(null=True)
my view where I try to join the lists
def pages(request, id):
obj = programas.objects.get(id=id)
script = programas.objects.values_list('script')
script_eng = programas.objects.values_list('script_eng')
zip_scripts = list(zip(script , script_eng))
context = {'title': obj.title,
'show_date': obj.show_date,
'script' : obj.script,
'script_eng': obj.script_eng,
'description': obj.description,
'description_eng': obj.description_eng,
'show_id':obj.show_id,
'url': obj.url,
'zip_scripts' : zip_scripts,
}
return render(request, 'rtves/pages.html', context)
my code on the template page
{% if script %}
{% for text1, text2 in zip_scripts %}
<p> {{ text1 }} </p>
<p> {{ text2 }} </p>
{% endfor %}
{% else %}
<p>Nothing here</p>
{% endif %}
Have I got to make changes in the database?
programas.objects.values_list('script') gives you a list of the script fields of all the programas objects in the database. So, you effectively have a list of lists.
What you probably want is just the fields from the object you already have. So there's no need to use values_list there.
obj = programas.objects.get(id=id)
script = obj.script
script_eng = obj.script_eng
or, just pass them straight to the zip (note, there's no need for list anyway):
obj = programas.objects.get(id=id)
zip_scripts = zip(obj.script, obj.script_eng)
The reason it "doesn't" work on your perspective is that because when you cast querysets to built-in iterables, you don't get, an an iterable of the values but an iterable of one item tuples like
[('bill',), ('while',), ('participant',), ('you',)]
which, when you cast zip and list upon becomes even weirder, but you can simply flatter this with something like
list(map(o.itemgetter(0), qs))
In your case the whole code would be roughly
flatten = lambda qs: list(map(operator.itemgetter(0), qs))
script = flatten(programas.objects.values_list('script'))
script_eng = flatten(programas.objects.values_list('script_eng'))
# Then you can just zip them together and have what you wanted to begin with
zip_scripts = list(zip(script , script_eng))
I have these models and I need to do some calculations and present them to the user. I render approx 2-3k of rows which results in 4k queries done to the DB (shown from debug toolbar). Is there any way to optimize this? I've tried with prefetch_related but it just adds another query on top of 4k already that are being done..
class Cart(models.Model):
name = models.CharField(max_length=15)
user = models.OneToOneField(User)
def sum_for_this(self, taxtype, tax):
return self.carttax_set.filter(tax__type__name=taxtype,
tax__tax=tax).aggregate(
sum=Coalesce(Sum('tax_amount'), Value('0'))
).get('sum')
class TaxType(models.Model):
name = models.CharField(max_length=10)
class Tax(models.Model):
name = models.CharField(max_length=100)
type = models.ForeignKey(TaxType)
tax = models.DecimalField()
class CartTax(models.Model):
cart = models.ForeignKey(Cart)
tax = models.ForeignKey(Tax)
base = models.IntegerField()
tax_amount = models.IntegerField()
What I do in template is:
{% for cart in cartlist %}
{{ cart.sum_for_this }}
{% endfor %}
I've tried with this but no effect:
Cart.objects.prefetch_related('carttax_set').all()
That method def sum_for_this is doing all the queries..
Try to use annotate with conditional expressions. Your query will look like this:
from django.db.models import Q, F, Sum, Case, When, IntegerField
from django.db.models.functions import Coalesce
cartlist = Cart.objects.annotate(
sum=Coalesce(Sum(Case(
When(Q(carttax__tax__type__name=taxtype) & Q(carttax__tax__tax=tax), then=F('carttax__tax_amount')),
output_field=IntegerField()
)), 0)
)
And in template:
{% for cart in cartlist %}
{{ cart.sum }}
{% endfor %}
This is my model:
class Feature(models.Model):
name = models.CharField(max_length=75, blank=True)
order = models.SmallIntegerField()
group = models.ForeignKey(FeatureGroup)
def __unicode__(self):
return self.name
class Meta:
ordering = ['order']
The "Features" are being correctly display in the admin control panel based on the value specified in "order".
I have this in my view:
p = get_object_or_404(Phone.objects.prefetch_related('brand', 'features__feature', 'photo_set'), id=id)
I templates I have {% for feature in phone.features.all %}... {{ feature.feature }} ...
The values are being displayed correctly but in random order.
What's wrong and how can I overcome this problem?
Thanks.
How about the template filter dictsort
https://docs.djangoproject.com/en/dev/ref/templates/builtins/#dictsort
{% for feature in phone.features.all|dictsort:"order" %}