python - How to use 2 ForeignKey filters one by one in 1 view - Django? -

hello , thank your answer:

my taks: show article, show 3 questions (related article), show 3 answer each queston (related these questions). coomon test page.

my models:

class step(models.model):  #main article     title = models.charfield(max_length=200)     description = models.charfield(max_length=200)     annotation = models.textfield()     main_text = models.textfield()         def __str__(self):         return self.title  class question(models.model): #questios related article.     step = models.foreignkey(step, on_delete=models.cascade)     title = models.charfield(max_length=200, default = "pages")     question_text = models.textfield()     question_name = models.charfield(max_length=40, help_text="английские буквы", blank=true, null=true)  class answer(models.model): #answers related questions     question = models.foreignkey(question, on_delete=models.cascade)     choice_text = models.textfield()     votes = models.integerfield(default=0)     answer_name = models.charfield(max_length=40, help_text="английские буквы", blank=true, null=true) 

how should works

i use identificator in url, show django article should show. helps me filtrs questions article. , should filted answers each question, have got previously. there many articles, questions , answers, can't use objects().all.

url(r'^question(?p<question_id>[0-9]+)$', 'bakot.views.question', name='question'), #urls.py  def question(request, question_id):     stepfields = get_object_or_404(step, id = question_id) #get article     questionship = question.objects.filter(step_id = question_id) #get questions, related article.     answership = questionship.prefetch_related().all #this doesn't work. , couldn't use coommon filter, don't know id them. or set id , show same answers 3 questions.             context = {         "stepfieldst" : stepfields,         "questionship" : questionship,         "answership" : answership,     }     return render(request, 'bakot/question.html', context) 

how show in template: (the part questions ans answers)

{% block question_area %}   {% question in questionship %}   <div class="small-12 medium-12 large-12 test-remark">     <legend><strong>{{ question.title }}&nbsp;</strong>{{ question.question_text }}</legend>        <ul class="menu vertical">          {% answer in answership  %}         <li>           <ul class="menu test-answer-padding navigation_hover_link11">             <li class="test-dot-padding"><input type="radio" name="{{ question.question_name }}" value="{{ answer.answer_name }}" id="pokemonred" required></li>             <li><label for="pokemonred">{{ answer.choice_text }}</label>           </ul>         </li>          {% endfor %}        </ul>    </div>   {% endfor %} {% endblock %} 

there few things here provide best solution.

first, don't need include questionship , answership in context. template can them via stepfields.questions , question.answers.

next, limit list 3, implement template filter. done using slices, this:

register = template.library()  @register.filter def limit_to_3(list, arg):     return list[0:arg] 

you then, in template, change {% %} loops format:

{% question in stepfieldst.questions|limit:3 %}     {% answer in question.answers|limit:3 %}     {% endfor %} {% endfor %} 

depending if number of questions , answers per article low enough querying them less burdensome multiple queries, this:

try:     stepfieldst = step.objects.select_related(questions__answers).filter(id = question_id) except step.doesnotexist:     raise http404 

this select related questions , answers in single query.