Im trying to using a ordered list in HTML to list the items in my querylist for some reason the ordering is not happening..
The list is diplayed but not ordering.
Here is my Django code,
<o1>
{% for t in teamrel %}
<li> {{t.teamrelation}} </li>
{% endfor %}
</o1>
Here is my output in the HTML code,
Patron Relations Team Volunteer Relations Team Volunteer Relations Team
its not getting ordered.
Let me know your inputs.
The main problem is that your code sample appears to have an <o1> tag (o+ONE) instead of <ol> (o+L).
Probably because <o1> shoudl be <ol>.
Otherwise, the QuerySet needs to be ordered correctly with an queryset.order_by('foo') call. Regardless of invalid tags, the output should be ordered.
You can print print queryset.query to see the actual ordering asked of the database.
Related
I'm trying to display a list of tickets in an HTML table. The table has various headings to display various aspects of the tickets. I would like to present this same table in a bunch of different locations across my project.
I've made a single template of /templates/shared/ticket_list.html in which presents the ticket list and then I {% include %} it where I need to display this listing. Simple enough.
However, there are a couple of pages in my project where I have a Bootstrap tabbed div. I want to display this table of tickets in both tabs, but with a different set of tickets. The HTML for this essentially requires that I {% include %} my table template twice on the same HTML page.
For example:
Tab 1: "Created By User" -- a list of tickets that the current user created
Tab 2: "Assigned To User" -- a list of tickets that are assigned to the current user
In the view, I might have something like:
created_by_ticks = Ticket.objects.filter(created_by = self.request.user)
assigned_to_ticks = Ticket.objects.filter(assigned_to = self.request.user)
The problem is, in my ticket table template, how would I present both querysets since the table itself is likely expecting a single variable name, such as:
{% for t in tickets %}
<tr>...
{% endfor %}
But passing in two querysets of tickets, I now have two ticket variables of created_by_ticks and assigned_to_ticks.
Any ideas how I could use that single ticket table template, but use multiple variables, or some other solution?
You can use the with functionality of the include tag:
{% include 'shared/ticket_list.html' with tickets=created_by_ticks %}
{% include 'shared/ticket_list.html' with tickets=assigned_to_ticks %}
In a Django template, I'm iterating over a set of photos, and displaying them one by one. Specifically, right now I just have one photo set, containing 6 objects. I display these 6 objects like so:
{% for pic in picstream.photo_set.all reversed %}
<img src="{{ pic.image_file.url }}"></img>
{% endfor %}
Adding reversed to the statement gives me the 6 objects in the desired ordering (i.e. the latest ids first).
Next, I want to display not more than 4 objects from the photo_set. I added |slice:":4" to picstream.photo_set.all to achieve this. Problem is, it's cutting off the first two objects from my desired oredering.
It seems there ought to have been a way to reverse the list first, and slice later? Need a simple way to do this, without performance compromises.
Instead of using the reversed argument for the for template tag, you can use the reverse method of the queryset itself:
{% for pic in picstream.photo_set.all.reverse|slice:":4" %}
<img src="{{ pic.image_file.url }}"></img>
{% endfor %}
If you are evaluating the original (non-reversed) queryset somewhere else in your code then this will result in a second query hitting the database. If this is the case then you are better off moving the logic into your view code itself or into a template tag.
I can fetch the data like this.
value= mymodel.objects.get(anycondition)
OR
value= mymodel.objects.filter(anycondition)
and can send them to my template with context.
But if I want to select all the data from a table(for all users not only one) as this query does
value= mymodel.objects.all()
and send this value to my template and can see there field by field
e.g.
my table has two fields name and phone no and I use the above query( value= mymodel.objects.all()) now if i want to see all names then i can see that and if i want to see phone no. I can see that too.
I have tried this and it doesn't work and I even I do not know it is possible or not.
If it is possible then please let me know how I can do this ?
I hope you understand my question. !!
Thanks in advance
.all() will return a list of objects that represent the rows in your model. .get() only returns one object. Your template is trying to print the result of all() if it was one object.
This is the same as if you had a list and you wanted to loop through it. In your view you would do:
product = Product_attributes.objects.all()
for i in product:
print i.size
print i.color
The equvalent for the template is:
<ul>
{% for i in product %}
<li>{{ i.size }}</li>
<li>{{ i.color }}</li>
{% endfor %}
</ul>
Although this question isn't clear it seems like you are having a bit of problem with Field Lookups. It is fairly easy to learn Here is a link to get you started
I am having trouble in understanding how to iterate over QuerySet , Tuple and Dictionarty in django.
I am confused which djnago functions returns what like objects.all or objects.get
Suppose i have
a = model.objects.all()
b = model.object.get(pk=1)
c = Blog.objects.values('name', 'entry__headline')
d = Entry.objects.values_list('id', 'headline')
e = Person.objects.raw('SELECT * FROM myapp_person')
What is the retured in each scenario and the biggest problem is how can i iterate over.
All these confuse me very much . I studies the docs but they tell one thing and don't tell how to use in template. I know its related to python but then python don't have template to deal with
QuerySet: A Django class that processes SQL responses and returns a python construct representing the results. Although it functions like a list in many ways, it's actually what's called an "iterable". It simply mocks the behavior of a list to allow you to use things like for-loops on it.
Tuple: An immutable list. That means that once it's set, it can't be altered. In virtually every other way it behaves just like a list.
Dictionary: Also known as a hash in other languages. It can be considered a "keyed list". A "list" in the strictest of senses is a group of items stored serially in memory. In the old days of programming, you'd have to "pop" items off and "push" items onto a list, and they could only be retrieved in a FIFO, or first-in-first-out fashion. Dictionaries provide a way to "lookup" items in a list. It is composed of key-value pairs, so you can reference a key and get the attached value.
Now in terms of Django templates:
QuerySets: You iterate over these using the standard methods. Once you get a result from something like MyModel.objects.all(), you can use a {% for value in queryset %} tag.
Tuples: As far as iteration goes, these behave exactly as standard lists. You can also just simply use a {% for value in tuple %} tag. The only potential hangup is that sometimes you'll end up with tuples of tuples or a list of tuples. These are just like multi-level lists. You have to iterate over the outer list or tuple and then iterate over the inner ones.
Dictionaries: These are probably the most complicated, only because they require a method call to get an iterable object.
mydict.iteritems() # returns an iterable consisting of `(key, value)` tuples.
mydict.iterkeys() # returns an iterable consisting of the keys. You can then use mydict[key] to get the values
mydict.itervalues() # returns an iterable consisting of the values.
The last method is probably the best of simple iteration in a Django template:
{% for value in mydict.itervalues %}
Are you referring to these docs? https://docs.djangoproject.com/en/dev/ref/templates/builtins/#for
I think that's what you were looking for.
Basically you iterate over them like:
{% for item in a %}
{{item.field}}
{{item.field2}}
{% endfor %}
{{b.field}}
{% for item in c %}
{{item.name}}
{{item.entry__headline}}
{% endfor %}
{% for item in d %}
{{item}}
{% endfor %}
# Also you can do this if you want to access just a particular index:
{{d.0}}
{{d.1}}
{% for item in e %}
{{item.field}}
{{item.field2}}
{% endfor %}
As for your data types:
a would be a QuerySet or list of model objects
b would be a model object
c would be a ValuesQuerySet or a list of dictionaries
d would also be a ValuesQuerySet but it's actually a list of tuples
e would be a RawQuerySet, which acts like a normal QuerySet
Sources:
https://docs.djangoproject.com/en/dev/topics/db/sql/#django.db.models.Manager.raw
https://docs.djangoproject.com/en/dev/ref/models/querysets/#values
https://docs.djangoproject.com/en/dev/ref/models/querysets/#values-list
I want to list the number of items for each list. How can I find this number in a single query, rather than a query for each list?
Here is a simplified version of my current template code:
{% for list in lists %}
<li>
{{ listname }}:
{% with list.num_items as item_count %}
{{ item_count }} item{{ item_count|pluralize }}
{% endwith %}
</li>
{% endfor %}
lists is passed as: List.objects.filter(user=user)
and num_items is a property of the List model:
def _get_num_items(self):
return self.item_set.filter(archived=False).count()
num_items = property(_get_num_items)
This queries SELECT COUNT(*) FROM "my_app_item" WHERE... n times, where n is the number of lists. Is it possible to make a single query here?
You should do this in your view and send the dictionary, instead.
Model.objects.values_list('item').annotate(Count('num_items'))
This will produce the SQL same as, (or equivalent to) the one you have posted.
In the following, I tried to take into account all your constraints: filtering on fields of List, on fields of Item, counting items , and grouping by list.
The solution I see is that you could use values() (here is the django doc about this : http://docs.djangoproject.com/en/dev/topics/db/aggregation/#values)
from django.db.models import Count
lists = list(List.objects.filter(user=user))
items=Item.objects.values(list).filter(archived=False,list__in=lists).annotate(count=Count("id"))
#you will get a list of dicts of the form [{'count':2,'list':5},...] where 5 is the id of the list
#now, you can match you list with you item counts in python
list_items_count_dict={}
for item in items:
list_items_count_dict[item['list']]=item['count']
for list in lists :
list.item_count = list_items_count_dict.get(list.id)
That will make only 2 queries, one for getting the lists, the other for computing the item counts. Afterwards, you will have two loops (that could probably be replaced by list comprehension one-liners ), but only for the lists you are interested in.
afterwards, in your template, you can use
{{list.item_count}}
There might be a more elegant option, but that is what I have found right now. I am also certain that you could reduce the number of query to one by using custom sql.
Disclaimer: I have not tested this code, but I have tested similar code on similar models. You could have problems because list is one of the keyword of the Python language.