Django 建模唯一的 6 位银行支票号码

Question

我尝试在 django doc 的帮助下设置唯一的 6 位校验码。但我仍然不想要想要的结果意味着它接受任何数字或字符，但我希望这将只接受 6 个整数，并确保该数字对所有用户都是唯一的

models.py

from django.db import models
from django.contrib.auth.models import User
from datetime import datetime
from uuid import uuid4
import string
from string import digits

class Mvouchar(models.Model):
cheque_no = models.CharField(max_length=6, null=True, blank=True, unique=True)
dated = models.DateTimeField(auto_now_add=True,null=True, blank=True)
def id_generator(size=6, chars=string.digits):
        return ''.join(random.choice(chars) for _ in range(size))

    def save(self):
        if not self.cheque_no:
            self.cheque_no = id_generator()
            while Mvouchar.objects.filter(cheque_no=self.cheque_no).exists():
                self.cheque_no = id_generator()
                self.dated = datetime.now()
        super(Mvouchar, self).save()    
    def __str__(self):
        if self.related:
            return self.related.relation.username.title()
        else:
            return 'no related!'
    class Meta:
            verbose_name_plural = "Single Cheque Multiple Vouchar Of Users"

views.py

def mvouchar(request):
            if request.method == "POST":
                userdata = User.objects.get(username = request.user)
                accountdata = Signs.objects.get(relation_id=userdata.id)
        chq_no = request.POST['chequeno']
        mini = Mvouchar(related_id=accountdata.id,  cheque_no = chq_no)
                mini.save()
                messages.success(request, "Your Cheque is Created") 
                return HttpResponseRedirect("/mvouchar/")           
            return render(request, 'cheque/mvouchar.html', {})

Answer 1

在此类示例中使用表单是标准做法，但我仍然考虑了您的示例并给出了我的解决方案。希望这对你有用。

models.py：

##change modelfield type
class Mvouchar(models.Model):
  cheque_no = models.PositiveIntegerField(validators=[MaxValueValidator(6)], unique=True)

views.py：

def mvouchar(request):
            if request.method == "POST":
                userdata = User.objects.get(username = request.user)
                accountdata = Signs.objects.get(relation_id=userdata.id)
        chq_no = request.POST['chequeno']
        ##verify chq_no
        if len(chq_no)==6 and chq_no.isdigit():
           if Mvouchar.objects.filter(cheque_no =chq_no):
              ##raiseError chq_no is already exists and return
           ##your further code
        else:
           ##raiseError chq_no is wrongly typed

Answer 2

您应该使用 ModelForm 来验证发布的数据。由于您在 cheque_no 模型字段上设置了 unique=True，因此表单会为您检查。

class MvoucharForm(forms.ModelForm):
    class Meta:
        fields = ('cheque_no',)

    def clean_cheque_no(self):
        cheque_no = form.cleaned_data['cheque_no']
        if not cheque_no.isdigit():
            raise forms.ValidationError('Please enter digits only')
        return cheque_no

...

def mvouchar(request):
    if request.method == "POST":
        form = MvoucharForm(request.POST(
        if form.is_valid():
            accountdata = Signs.objects.get(relation=request.user)
            mini = form.save(commit=False)
            mini.related = accountdata
            mini.save()
            messages.success(request, "Your Cheque is Created") 
            return HttpResponseRedirect("/mvouchar/")
     else:
         form = MvoucharForm()
     return render(request, 'cheque/mvouchar.html', {'form': form})

并且不要忘记在模板中使用form，尤其是{{ form.errors }}。