CODEWITHSUNDEEP
pythondjangodjango-rest-framework
Peter Gould
Peter Gould

Reputation: 93

Django api backend filter table

The goal is to get the photos associated with a listing id. I have the bellow structure in django rest framework

Model.py

class Pictures(models.Model):
    index = models.BigIntegerField(blank=True, null=True)
    listing_id = models.ForeignKey(
        Listings, models.DO_NOTHING, blank=True, null=True)
    post_title = models.TextField(blank=True, null=True)
    guid = models.TextField(blank=True, null=True)
    post_mime_type = models.TextField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'pictures'

Serializer.py

class PicturesSerializer(serializers.ModelSerializer):
    class Meta:
        model = Pictures
        fields = ('index', 'listing_id', 'guid')

Views.py

class PicturesListViewAlt(generics.ListAPIView):
    serializer_class = PicturesSerializer

    def get_queryset(self):
        if self.request is None:
        return Pictures.objects.none()
    id_of_listing = self.kwargs['listing_id']
    return Pictures.objects.filter(listing_id=id_of_listing)

urls.py

app_name = 'pics'

    urlpatterns = [
    re_path('^pictures/(?P<listing_id>.+)/$',
            views.PicturesListViewAlt.as_view()),
]

I keep getting the bellow errors.

django.db.utils.ProgrammingError: column pictures.listing_id_id does not exist
LINE 1: ...ELECT COUNT(*) AS "__count" FROM "pictures" WHERE "pictures"...
                                                             ^
HINT:  Perhaps you meant to reference the column "pictures.listing_id".

[03/Feb/2022 11:58:17] "GET /api/pictures/123/ HTTP/1.1" 500 24360

Although I have never initiated a column listing_id_id

And

    ProgrammingError at /api/pictures/123/
    column pictures.listing_id_id does not exist
    LINE 1: ...ELECT COUNT(*) AS "__count" FROM "pictures" WHERE "pictures"...
                                                                 ^
    HINT:  Perhaps you meant to reference the column "pictures.listing_id".

Which when I change my filter to pictures__listing_id I get 

django.core.exceptions.FieldError: Cannot resolve keyword 'pictures' into field. Choices are: guid, id, index, listing_id, listing_id_id, post_mime_type, post_title
[03/Feb/2022 12:07:46] "GET /api/pictures/123/ HTTP/1.1" 500 22236

Sorry for the long question but I have been at it for hours. Any help is much appreciated. Cheers!

Upvotes: 1

Views: 111

Answers (1)

user8193706
user8193706

Reputation: 2425

From the Database Representation [Django-doc]

Behind the scenes, Django appends "_id" to the field name to create its database column name

That's the reason why it appends _id to your listing_id field and it searches for listing_id_id as column. So you don't have to add _id while declaring Model.

Change your Picture model as

class Pictures(models.Model):
    id = models.AutoField(primary_key=True)
    index = models.BigIntegerField(blank=True, null=True)
    listing = models.ForeignKey(Listings, models.DO_NOTHING, blank=True, null=True)
    post_title = models.TextField(blank=True, null=True)
    guid = models.TextField(blank=True, null=True)
    post_mime_type = models.TextField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'pictures'

Also change your Serializer.py as

class PicturesSerializer(serializers.ModelSerializer):
    class Meta:
        model = Pictures
        fields = ('index', 'listing', 'guid')

Upvotes: 2

Related Questions