以uuid作为primaryKey的Django IntegrityError

Question

好的，这里是行为的解释。

1。我通过管理面板创建一个新的Post对象。

2。对象已保存。

3。之后再创建一个Post对象。

4。获取错误

django.db.utils.IntegrityError：重复的键值违反了唯一约束“ lp_post_pkey”详细信息：键（id）=（5de7b062-14b2-42ef-a9ee-95bbb17ccf3b）已经存在。

我已阅读duplicate key value violates unique constraint in django。

问题可能与正在使用的表中的主键序列不同步。解决此问题的方法是将当前Primary Key设置为最大值+1。

但是我使用uuid作为主键，这可能不是我的解决方案。

所以，如果问题确实出在那，我该如何同步我的主键？

Btw，当我重置local server时，我可以从1-4开始重复步骤。

同样，当我执行manage.py makemigrations时，即使没有任何要迁移的地方，我也注意到，我的uuid字段不断更改为新字段。问题可以以某种方式关联吗？

models.py

class SubscriberModel(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4(), unique=True, editable=False)
    email = models.EmailField()
    subscribed = models.DateTimeField(default=timezone.now())
    ip_addr = models.CharField(null=False, max_length=250, default="")
    objects = models.Manager()

    def __str__(self):
        return "{%s}/EMAIL\{%s}/\Subscribed On/\{%s}/\From this IP" % \
               (self.email, self.subscribed, self.ip_addr)

    class Meta:
        unique_together = ('email', 'ip_addr')


class ContactUsModel(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4(), unique=True, editable=False)
    name = models.CharField(max_length=150, null=False)
    email = models.EmailField()
    body = models.TextField()
    ip_addr = models.CharField(null=False, max_length=250, default="")
    date = models.DateTimeField(default=timezone.now())
    objects = models.Manager()

    def __str__(self):
        return 'mail from {%s} | at {%s}' % (self.email, self.date)

    class Meta:
        unique_together = ('email', 'ip_addr')


def save_image(title, filename):
    return '{%s}-{%s}' % (title, filename)


class Post(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4(), unique=True, editable=False)
    title = models.CharField(max_length=250)
    body = models.TextField()
    main_image = models.ImageField(null=False, upload_to=save_image)
    second_image = models.ImageField(blank=True, default="")
    third_image = models.ImageField(blank=True, default="")
    fourth_image = models.ImageField(blank=True, default="")
    fifth_image = models.ImageField(blank=True, default="")
    created_at = models.DateTimeField(default=timezone.now())

    # get url

    def slug(self):
        return slugify(self.title)

    def get_absolute_url(self):
        return reverse('lp:post_detail', kwargs={'slug': self.slug(),
                                                 'pk': self.pk})

    def __str__(self):
        return '%s' % self.title

    class Meta:
        ordering = ['-created_at']

完整回溯

追踪（最近一次通话）：文件“ /venv/lib/python3.7/site-packages/django/db/backends/utils.py”，_execute中的第86行返回self.cursor.execute（sql，params）psycopg2.errors.UniqueViolation：重复的键值违反唯一约束“ lp_post_pkey”详细信息：键（id）=（5de7b062-14b2-42ef-a9ee-95bbb17ccf3b）已经存在。

我最近的2次迁移

class Migration(migrations.Migration):

    dependencies = [
        ('lp', '0008_auto_20191221_2016'),
    ]

    operations = [
        migrations.AlterField(
            model_name='contactusmodel',
            name='date',
            field=models.DateTimeField(default=datetime.datetime(2019, 12, 21, 20, 17, 10, 770047, tzinfo=utc)),
        ),
        migrations.AlterField(
            model_name='contactusmodel',
            name='id',
            field=models.UUIDField(default=uuid.UUID('37e52230-3c82-45eb-bbb9-aeb432b12247'), editable=False, primary_key=True, serialize=False, unique=True),
        ),
        migrations.AlterField(
            model_name='post',
            name='created_at',
            field=models.DateTimeField(default=datetime.datetime(2019, 12, 21, 20, 17, 10, 770612, tzinfo=utc)),
        ),
        migrations.AlterField(
            model_name='post',
            name='id',
            field=models.UUIDField(default=uuid.UUID('f4e05be4-2722-47b2-b636-232079114157'), editable=False, primary_key=True, serialize=False, unique=True),
        ),
        migrations.AlterField(
            model_name='subscribermodel',
            name='id',
            field=models.UUIDField(default=uuid.UUID('61b77cb5-5f33-4b8b-b235-83d3b10cc989'), editable=False, primary_key=True, serialize=False, unique=True),
        ),
        migrations.AlterField(
            model_name='subscribermodel',
            name='subscribed',
            field=models.DateTimeField(default=datetime.datetime(2019, 12, 21, 20, 17, 10, 741394, tzinfo=utc)),
        ),
    ]


class Migration(migrations.Migration):

    dependencies = [
        ('lp', '0007_auto_20191221_2004'),
    ]

    operations = [
        migrations.AlterField(
            model_name='contactusmodel',
            name='date',
            field=models.DateTimeField(default=datetime.datetime(2019, 12, 21, 20, 16, 18, 987126, tzinfo=utc)),
        ),
        migrations.AlterField(
            model_name='contactusmodel',
            name='id',
            field=models.UUIDField(default=uuid.UUID('fabeec4c-bdd0-443a-81e9-2ea0ba8c8f4b'), editable=False, primary_key=True, serialize=False, unique=True),
        ),
        migrations.AlterField(
            model_name='post',
            name='created_at',
            field=models.DateTimeField(verbose_name=datetime.datetime(2019, 12, 21, 20, 16, 18, 987702, tzinfo=utc)),
        ),
        migrations.AlterField(
            model_name='post',
            name='id',
            field=models.UUIDField(default=uuid.UUID('aafc7ac3-f48b-4a74-a9cd-2af3a8d3fcae'), editable=False, primary_key=True, serialize=False, unique=True),
        ),
        migrations.AlterField(
            model_name='subscribermodel',
            name='id',
            field=models.UUIDField(default=uuid.UUID('b9c2a42c-3265-4a13-af48-ff5db4f38d30'), editable=False, primary_key=True, serialize=False, unique=True),
        ),
        migrations.AlterField(
            model_name='subscribermodel',
            name='subscribed',
            field=models.DateTimeField(default=datetime.datetime(2019, 12, 21, 20, 16, 18, 958998, tzinfo=utc)),
        ),
    ]

Answer 1

您的问题是您将默认设置为uuid.uuid4()。当应用程序第一次启动时，这将创建一个id，然后尝试对每个帖子使用相同的id。

解决方案是使用不带括号的default=uuid.uuid4。这将自动为每条记录执行该函数，并生成一个新的uuid。