How to Filter within a Filter in Django-CodePudding

I'm trying to filter category with age range. I want to see people with certain genders and then their age range.

My models:

from django.db import models

# Create your models here.

class catagory(models.Model):
    name = models.CharField(max_length=150)

    def __str__(self):
        return self.name


class Age(models.Model):
    range = models.CharField(max_length=150)

    def __str__(self):
        return self.range


class person(models.Model):
    name = models.CharField(max_length=100)
    gender = models.ForeignKey(catagory, on_delete=models.CASCADE)
    age_range = models.ForeignKey(Age, on_delete=models.CASCADE)

    @staticmethod
    def get_person_by_cataegoryID(categoryID):
        if categoryID:
            return person.objects.filter(gender=categoryID)
        else:
            return person.objects.all()

    @staticmethod
    def get_person_by_age_range(AGE_RANGE):
        if AGE_RANGE:
            return person.objects.filter(age_range=AGE_RANGE)
        else:
            return person.objects.all()

    def __str__(self):
        return self.name

My views

    from django.shortcuts import render
from .models import catagory,person,Age

# Create your views here.

def index(request):
    c = catagory.objects.all()
    categoryID = request.GET.get('category')
    AGE_RANGE = request.GET.get('age_range')



    p= person.objects.all()
    a = Age.objects.all()
    if categoryID:
        persons = person.get_person_by_cataegoryID(categoryID)
    elif AGE_RANGE:
        persons = person.get_person_by_age_range(AGE_RANGE)
    else:
        persons = person.objects.all()

    context = {
        "person": p,
        "catagory": c,
        "age": a
    }

    context["person"] = persons

    return render(request, "index.html", context)

My Template

    <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h2>hello</h2>
<div style="display:flex;height:100vh;width:100vw;align-items:center;justify-content:space-around;">

    <div style="display:flex;flex-direction:column;">
        {% for a in age %}
        <a href="/?age_range={{a.id}}">{{a.range}}</a>
        {% endfor %}
    </div>
  <div style="display:flex;flex-direction:column;">
      <a href="/">All</a>
    {% for c in catagory %}
      <a href="/?category={{c.id}}">{{c.name}}</a>
    {% endfor %}
  </div>
  <br>
  <div style="display:flex;flex-direction:column;">
    {% for p in person %}
      <p>{{p.name}}</p>
     {% endfor %}

  </div>
</div>

</body>
</html>

Please tell me what I'm doing wrong here. The filters work by themselves correctly but my goal is to see a specific gender and then that gender's age range. Currently it shows the gender and age range of the whole group.

CodePudding user response：

if you need gender and age at the same time:

if categoryID and AGE_RANGE:
    persons = person.objects.filter(gender=categoryID, age_range=AGE_RANGE)     
elif categoryID:
    persons = person.get_person_by_cataegoryID(categoryID)
elif AGE_RANGE:
    persons = person.get_person_by_age_range(AGE_RANGE)
else:
    persons = person.objects.all()

CodePudding user response：

You can use ** dictionary unpacking to determine your model filters. The dictionary itself is created based on whether category/age_range exist in request.GET:

category = request.GET.get('category')
age_range = request.GET.get('age_range')

filters = {}
if category:
    filters['category'] = categoryID
if age_range:
    filters['age_range'] = AGE_RANGE
    
persons = person.objects.filter(**filters)

If filters is an empty dict then it has the same effect as calling all()

Edit - you could also use a list an dict comprehension to remove the if-statement:

fields = ['category','age_range']
filters = {k: v for k, v in request_GET.items() if k in fields and v is not None}