Django Inline for ManyToMany generate duplicate queries

Question

I\'m experiencing some major performing issue with my django admin. Lots of duplicate queries based on how many inlines that I have.

models.py

class          


        

Answer 1

Nowadays, (kudos to that question), BaseFormset receives a form_kwargs attribute.

The ChoicesFormSet code in the accepted answer could be slightly modified as such:

class ChoicesFormSet(forms.BaseInlineFormSet):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        setting_choices = list(Setting.objects.values_list('id', 'name'))
        displayed_group_choices = list(DisplayedGroup.objects.values_list('id', 'name'))
        self.form_kwargs['setting_choices'] = self.setting_choices
        self.form_kwargs['displayed_group_choices'] = self.displayed_group_choices

The rest of the code stays intact, as desscribed in the accepted answer:

class ArrangementInlineForm(forms.ModelForm):
    class Meta:
        model = Arrangement
        exclude = ()

    def __init__(self, *args, **kwargs):
        setting_choices = kwargs.pop('setting_choices', [((), ())])
        displayed_group_choices = kwargs.pop('displayed_group_choices', [((), ())])

        super().__init__(*args, **kwargs)

        # This ensures that you can still save the form without setting all 50 (see extra value) inline values.
        # When you save, the field value is checked against the "initial" value
        # of a field and you only get a validation error if you've changed any of the initial values.
        self.fields['setting'].choices = [('-', '---')] + setting_choices
        self.fields['setting'].initial = self.fields['setting'].choices[0][0]
        self.fields['setting'].empty_values = (self.fields['setting'].choices[0][0],)

        self.fields['displayed_group'].choices = displayed_group_choices
        self.fields['displayed_group'].initial = self.fields['displayed_group'].choices[0][0]


class ArrangementInline(admin.TabularInline):
    model = Arrangement
    extra = 50
    form = ArrangementInlineForm
    formset = ChoicesFormSet

    def get_queryset(self, request):
        return super().get_queryset(request).select_related('setting')


class MachineAdmin(admin.ModelAdmin):
    inlines = (ArrangementInline,)


admin.site.register(Machine, MachineAdmin)