django-无法分配"u'Joan Manel'":"despesa.nomTreballador"必须是"treballador"实例 [英] django-Cannot assign "u'Joan Manel'": "despesa.nomTreballador" must be a "treballador" instance

问题描述

我一直在从事一个项目，在该项目中我必须指出公司员工的支出.

I have been working on a project in which I have to point out the expenses that the workers of a company have.

为此，我创建了两个模型:工作人员和费用，其中费用对工作人员具有外键:"nomTreballador".

For this I have created two models, workers and expenses, in which expenses has a foreign key to workers, in the field: "nomTreballador".

当我尝试将其保存在数据库中时，出现错误:无法分配"u'Joan Manel'":"despesa.nomTreballador"必须是"treballador"实例."

When I try to save it in the db I get the error: "Cannot assign "u'Joan Manel'": "despesa.nomTreballador" must be a "treballador" instance."

我的模型.py:

from __future__ import unicode_literals
from django.db import models
from django.core.validators import RegexValidator

KILOMETRATGE = 'KM'
DINAR = 'DIN'
AUTOPISTA = 'AP'
MANTENIMENTPC = 'PC'

GASTOS = (
    (KILOMETRATGE, 'Kilometres'),
    (DINAR, 'Dinar'),
    (AUTOPISTA, 'Autopista peatge'),
    (MANTENIMENTPC, 'Manteniment de pc')
)

NIF = 'NIF'
NIE = 'NIE'
DNI = 'DNI'

TIPUSDOC = (
    (DNI, 'DNI'),
    (NIF, 'NIF'),
    (NIE, 'NIE')
)

class treballador(models.Model):
    nom = models.CharField(max_length=150, null=False, unique=True)
    cognom = models.CharField(max_length=150, null=False)
    tipusDocID = models.CharField(max_length=3, choices=TIPUSDOC, null=False)
    docId = models.CharField(max_length=9, null=False)
    tlf_regex = RegexValidator(regex=r'^\d{9,9}$',message="Phone number must be entered in the format: '[phone]'. Up to 9 digits allowed.")
    tlf = models.CharField(validators=[tlf_regex], blank=True, max_length=9)  # validators should be a list
    correu = models.EmailField(max_length=254)
    ciutat = models.CharField(max_length=150)
    dataDAlta = models.DateTimeField(auto_now_add=True)
    def __unicode__(self):
        return unicode(self.nom) or 'u'

   class despesa(models.Model):
        nomTreballador = models.ForeignKey(treballador, to_field='nom')
        tipusDeGast = models.CharField(max_length=3, choices=GASTOS)
        quantia = models.DecimalField(max_digits=5, decimal_places=2)
        data = models.DateTimeField()

    def __unicode__(self):
        return unicode(self.nomTreballador) or 'u'

我的forms.py:

My forms.py:

from django import forms
from functools import partial
from .models import despesa, treballador

DateInput = partial(forms.DateInput, {'class':'datepicker'})

class desModelForm(forms.ModelForm):
    data = forms.DateField(widget=DateInput(format='%d/%m/%Y'), label="Data    de la despesa", input_formats=['%d/%m/%Y'])
    iquery = treballador.objects.values_list('nom', flat=True).distinct()
    iquery_choices = [('','None')] + [(treballador,treballador) for treballador in iquery]
    nomTreballador = forms.ChoiceField(choices=iquery_choices)
    class Meta:
        model= despesa
        fields= ["nomTreballador","tipusDeGast","quantia","data"]

        def clean_despesa(self):
            despeses = self.cleaned_data.get("tipusDeGast")
            return despeses

        def clean_date(self):
            date = self.cleaned_data.get("data")
            return date

        def clean_quantia(self):
            quantia = self.cleaned_data.get("quantia")
            return quantia

        def clean_nom(self):
            nomTreballador = self.cleaned_data.get("nomTreballador")
            return nomTreballador

我的views.py:

My views.py:

from django.shortcuts import render
from .forms import desModelForm, treballadorForm
from .models import treballador, despesa

def home(request):
    form = desModelForm(request.POST or None)

    context = {
        "gast_form": form
    }


    if form.is_valid():
        desp = form.save(commit=False)
        desp.save()


    return render(request, "imputacioDespeses.html", context)

我已经尝试过类似问题的解决方案，但是我没有解决

I've tried solutions of similar questions but I have not managed to solve it

谢谢！

推荐答案

出现此错误的原因是，当您传递一个文本字符串用作 nomTreballador 外键时， treballador 实例.

You are getting this error because you are passing a text string to be used as the nomTreballador foreign key, while you should be passing a treballador instance.

您似乎正在尝试通过使用 forms.ChoiceField 将可用选项限制为一组不同的 trebellador ，但这是一种更好的方法使用ModelForm来更改 nomTreballador 字段的 queryset 属性.您可以通过表单的 init 方法执行此操作:

It looks like you're trying to restrict the available choices to a set of distinct trebelladors by using a forms.ChoiceField, but a better way to do this with a ModelForm is to change the queryset attribute of the nomTreballador field. You do this in the form's init method:

self.fields ['nomTreballador'].queryset = treballador.objects.all().distinct()

此外，您还应该检查已实现的 clean 方法，因为并非所有方法都映射到现有字段.

Also you should check the clean methods you've implemented because not all of them map to an existing field.

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