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pythondjangodjango-viewsdjango-forms

Field 'id' expected a number but got <QueryDict

This is a common error on stack overflow but I cannot draw similarities with their errors and mine.

A number is expected in the id column of the database(automatically made by django) but a query dict was put in instead.

(These are mode details so that I can post this post)

Model:

class Price(models.Model):
    HourlyPrice = MoneyField(default_currency="GBP",max_digits=19,decimal_places=3,null=True,blank=False) # price per hour
    DailyPrice = MoneyField(default_currency="GBP",max_digits=19,decimal_places=2,null=True,blank=True)# price per day
    WeeklyPrice = MoneyField(default_currency="GBP",max_digits=19,decimal_places=2,null=True,blank=True)# price per week
    MonthlyPrice = MoneyField(default_currency="GBP",max_digits=19,decimal_places=2,null=True,blank=True)# price per month

View:

def test(request):
    if request.method == 'POST':
        form = Price(request.POST)
        form.save()
        
        return render(request,'app/index.html',
        {
            'title':'Home Page',
            'year':datetime.now().year,
        }
        )

    else:
            form = TestPrice(request.GET)
            context = {
                'form': form,
            }
            return render(request,'app/test.html',context)

Template:

{% extends "app/layout.html" %}

{% block content %}

<form method="post" action="">
    {% csrf_token %}
    <table>
    {{form}}
    </table>
    <button type="submit">Submit</button> 
    </form>
    
{% endblock %}

Stack Trace:

File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\fields\__init__.py", line 2018, in get_prep_value
    return int(value)

The above exception (int() argument must be a string, a bytes-like object or a real number, not 'QueryDict') was the direct cause of the following exception:
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\core\handlers\exception.py", line 56, in inner
    response = get_response(request)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\core\handlers\base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\OneDrive\c_CodingFiles\SqlLite Learning\testing datetime\test\test\app\views.py", line 52, in test
    form.save()
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\base.py", line 812, in save
    self.save_base(
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\base.py", line 863, in save_base
    updated = self._save_table(
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\base.py", line 976, in _save_table
    updated = self._do_update(
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\base.py", line 1019, in _do_update
    filtered = base_qs.filter(pk=pk_val)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\query.py", line 1421, in filter
    return self._filter_or_exclude(False, args, kwargs)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\query.py", line 1439, in _filter_or_exclude
    clone._filter_or_exclude_inplace(negate, args, kwargs)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\query.py", line 1446, in _filter_or_exclude_inplace
    self._query.add_q(Q(*args, **kwargs))
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\sql\query.py", line 1532, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\sql\query.py", line 1562, in _add_q
    child_clause, needed_inner = self.build_filter(
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\sql\query.py", line 1478, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\sql\query.py", line 1303, in build_lookup
    lookup = lookup_class(lhs, rhs)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\lookups.py", line 27, in __init__
    self.rhs = self.get_prep_lookup()
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\lookups.py", line 341, in get_prep_lookup
    return super().get_prep_lookup()
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\lookups.py", line 85, in get_prep_lookup
    return self.lhs.output_field.get_prep_value(self.rhs)
  File "C:\Users\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\django\db\models\fields\__init__.py", line 2020, in get_prep_value
    raise e.__class__(

Thank you for your time

Solution

  • Likely one of the main problems is that you use Price as a form, but Price is a model, so passing request.POST (or request.GET) to it directly makes no sense.

    You define a ModelForm:

    from django import forms


class PriceForm(forms.ModelForm):
    class Meta:
        model = Price
        fields = '__all__'

    then you use that PriceForm in the view to validate the data and save the data in the database:

    from django.shortcuts import redirect

def test(request):
    if request.method == 'POST':
        form = PriceForm(request.POST, request.FILES)
        if form.is_valid():
            form.save()
            return redirect('name-of-some-view')
    else:
        form = PriceForm()
    return render(request, 'app/test.html', {'form': form})

    it makes no sense to work with request.GET in case of a GET request: in that case we perform the first request for that page, and thus we should render an empty form, not a form bounded by (possibly) empty data that then shows errors.

    Note: normally the name of the fields in a Django model are written in snake_case, not PascalCase, so it should be: hourly_price instead of HourlyPrice.

    Note: In case of a successful POST request, you should make a redirect [Django-doc] to implement the Post/Redirect/Get pattern [wiki]. This avoids that you make the same POST request when the user refreshes the browser.