Django exception: decimal.InvalidOperation: []

Question

I have strange behavor in code.

My model is:

class Item(models.Model):
    ....
    price = models.DecimalField(max_digits=5, decimal_places=2, help_text="Цена товара", verbose_name="Цена")
    # price = models.IntegerField(help_text="Цена товара", verbose_name="Цена")

When I try filter object:

class ProductBuyView(APIView):
    def get(self, request, item_uuid: str, format=None):
        product = Item.objects.all().filter(uuid__exact=uuid.UUID(item_uuid))[0]
        ...

I get an exception

File "/home/lev/python_projects/taste_case_stripe/stripe_app/views.py", line 14, in get
    product = Item.objects.all().filter(uuid__exact=uuid.UUID(item_uuid))[0]
  File "/home/lev/python_projects/taste_case_stripe/venv/lib/python3.10/site-packages/django/db/models/query.py", line 445, in __getitem__
    qs._fetch_all()
  File "/home/lev/python_projects/taste_case_stripe/venv/lib/python3.10/site-packages/django/db/models/query.py", line 1866, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "/home/lev/python_projects/taste_case_stripe/venv/lib/python3.10/site-packages/django/db/models/query.py", line 117, in __iter__
    for row in compiler.results_iter(results):
  File "/home/lev/python_projects/taste_case_stripe/venv/lib/python3.10/site-packages/django/db/models/sql/compiler.py", line 1333, in apply_converters
    value = converter(value, expression, connection)
  File "/home/lev/python_projects/taste_case_stripe/venv/lib/python3.10/site-packages/django/db/backends/sqlite3/operations.py", line 344, in converter
    return create_decimal(value).quantize(
decimal.InvalidOperation: []

...decimal.InvalidOperation: []

but when I change type field to Int

class Item(models.Model):
    ....
    price = models.IntegerField(help_text="Цена товара", verbose_name="Цена")

everthing is OK. As I guess the problem is decimal field. But what is wrong with it...

somesh · Answer

try this:

from django.db import models
from django.db.models import Model
# Create your models here.

class DecimalModel(Model):
    geeks_field = models.DecimalField(
                     max_digits = 5,
                     decimal_places = 2)

in view:

from geeks.models import DecimalModel

# importing datetime module
import decimal

# creating an instance of 
# datetime.date
d = decimal.Decimal(9.53)

# creating an instance of 
# DecimalModel
my_object = DecimalModel.objects.create(geeks_field = d)
my_object.save()

weAreStarsDust · Answer

I guess there is some problem with data in your database. Can you delete all data from your Item table? Problem should go away after this. As i see you use SQLight so you can copy db file as backup and try Item table clean to diagnose the source of problem.

Lev Kakalashvili · Answer

I found this. I changed DB to MySQL. And did the same query to MySQL storage. In this case the issue is disappeared.

Django exception: decimal.InvalidOperation: [<class 'decimal.InvalidOperation'>]

3 Answers