Question

如果给定的电子邮件已经在数据库中，但允许空值，我正在寻找单行过滤器查询。

forms.py

 def clean_email(self):
        email = self.cleaned_data.get('email')
        q = Email.objects.filter(email=email)
        if not email or q.count() == 0:
            return email
        raise forms.ValidationError('Podany email już widnieje w bazie')

models.py

class Email(models.Model):
    person = models.ForeignKey(Person, editable=False, on_delete=models.CASCADE)
    email = models.EmailField(max_length=70, blank=True)

Answer 1

您可以为此写validator：

from django.core.exceptions import ValidationError

def validate_email(value):
    q = Email.objects.filter(email=value)
    if not q.exists():
        return email
    raise ValidationError('Podany email już widnieje w bazie')

forms.py：

from django import forms

class EmailForm(forms.ModelForm):
    email = forms.EmailField(required=True, validators=[validate_email])

models.py：

from django.db import models

class Email(models.Model):
    person = models.ForeignKey(Person, editable=False, on_delete=models.CASCADE)
    email = models.EmailField(max_length=70, blank=True, validators=[validate_email])

Answer 2

您可以使用exists()

Email.objects.filter(email=email).exists()

返回True是找到一个实例。

查询电子邮件是否存在于数据库中并且不为空

2 个答案: