Django在模型表中添加手动校验的方式

下面的示例主要运用于代码层面的去重处理，不在数据库层面增加唯一键

# 导入依赖
from django.db import models
from django.utils.translation import gettext_lazy as _
from rest_framework.exceptions import APIException
from django.contrib.auth import get_user_model

User = get_user_model()

# 以书名为例
class Book(models.Model):
    author = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        related_name='books',
        verbose_name=_('作者')
    )
    name = models.CharField(null=True, blank=True, max_length=255, verbose_name=_('书名'))
    public_time = models.DateField(null=True, blank=True, verbose_name=_('发行时间'))
    is_delete = models.BooleanField(default=False, verbose_name=_('是否删除'))

    def __str__(self):
        return f'{self.name} - {self.author.name} - {self.public_time}'

    def clean(self):
        if not self.is_delete:
            # 检查是否已有相同的书名、作者 且 is_delete=False 的记录
            if VersionReviewPlan.objects.filter(
                    author=self.author,
                    name=self.name,
                    public_time=self.public_time,
                    is_delete=False
            ).exclude(pk=self.pk).exists():
                raise APIException('请检查是否存在相同的书名')

    def save(self, *args, **kwargs):
        self.clean()
        super().save(*args, **kwargs)

    class Meta:
        verbose_name = _('书名')
        verbose_name_plural = _('书名')