django:在Model.Forms上使用UniqueConstraint的ValidationError，clean()

from django import forms
from django.core.exceptions import ValidationError
from django.db.models import UniqueConstraint

class MyForm(forms.Form):
    my_field = forms.CharField()

    def clean(self):
        cleaned_data = super().clean()
        my_field_value = cleaned_data.get('my_field')

        # 使用UniqueConstraint验证字段唯一性
        if my_field_value:
            try:
                # 在这里执行唯一性验证操作
                # 如果验证失败，抛出ValidationError
                # 例如：UniqueConstraint(MyModel, ['my_field'])
                pass
            except:
                raise ValidationError('my_field必须是唯一的')

        return cleaned_data