Using Django-Filter to filter data from two related Models

Using Django Getting Started
1

Good day all,

I have a challenge in my project. I am using Django-Filter to generate report from my model, It works very fine using one Model and I can get all my report using the filter generated.

But when I tried to include the related table to pick some fields from the second table, I got the error Meta.fields must not contain non-model field names:

I used a sample codes I got online

Model.py

from django.db import models 

class Customer(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(unique=True)

class Order(models.Model):
    customer = models.ForeignKey(Customer, on_delete=models.CASCADE)
    order_date = models.DateField()
    total_price = models.DecimalField(max_digits=10, decimal_places=2)

Filter.py

import django_filters

class OrderFilter(django_filters.FilterSet):
    customer_name = django_filters.CharFilter(field_name='customer__name', lookup_expr='icontains')

    class Meta:
        model = Order
        fields = ['customer_name', 'order_date']

But still generating the error.

Any help will be highly appreciated.
Thanks.

2

This is stated on the documentation of the filterset.

Note that it is not necessary to include declared filters in a fields list - doing so will only affect the order in which fields appear on a FilterSet’s form. Including declarative aliases in a fields dict will raise an error.

So the correct declarion would be:

import django_filters

class OrderFilter(django_filters.FilterSet):
    customer_name = django_filters.CharFilter(field_name='customer__name', lookup_expr='icontains')

    class Meta:
        model = Order
        fields = ['order_date']  # customer_name not included on fields
3

Thank you very much. I reverted back to the configuration that worked.

parsed = urlparse(oReport.filter_params)
captured_value = parse_qs(parsed.query)
filter_params = {key: value[0] for key, value in captured_value.items()}
#queryset=Initiative.objects.filter(**filter_params)
queryset2=InitiativeImpact.objects.select_related('initiativeId').filter(**filter_params)

I then joined the tables in my views.py,

InitiativeImpact.objects.select_related('initiativeId').filter(**filter_params)

I was able to select all the fields and even the properties on the other table.

Thanks for the suggestion.

But, why can’t be a workaround by the django-filter project to fix this issue?

4

Maybe it should be something like

fields = ['customer__name', 'order_date']

? I don’t use Django-filters, but that’s how iommi works for the corresponding thing.

Note the double underscores.

5

It must have been fixed in iommi. Then django-filters should do the same.

Thank you very much.