Django-Postgres 完整性错误：重复密钥 --- 如何修复？

添加模型的新实例时出现完整性错误，这是回溯：

Traceback:
File "/home/robain/webapps/django/lib/python2.6/django/core/handlers/base.py" in get_response
  100.                     response = callback(request, *callback_args, **callback_kwargs)
File "/home/robain/webapps/django/lib/python2.6/django/contrib/admin/views/decorators.py" in _checklogin
  33.             return view_func(request, *args, **kwargs)
File "/home/robain/webapps/django/tmanage/tempManage/src/CTmanage.py" in addCT
  101.             CT.save()
File "/home/robain/webapps/django/lib/python2.6/django/db/models/base.py" in save
  434.         self.save_base(using=using, force_insert=force_insert, force_update=force_update)
File "/home/robain/webapps/django/lib/python2.6/django/db/models/base.py" in save_base
  527.                     result = manager._insert(values, return_id=update_pk, using=using)
File "/home/robain/webapps/django/lib/python2.6/django/db/models/manager.py" in _insert
  195.         return insert_query(self.model, values, **kwargs)
File "/home/robain/webapps/django/lib/python2.6/django/db/models/query.py" in insert_query
  1479.     return query.get_compiler(using=using).execute_sql(return_id)
File "/home/robain/webapps/django/lib/python2.6/django/db/models/sql/compiler.py" in execute_sql
  783.         cursor = super(SQLInsertCompiler, self).execute_sql(None)
File "/home/robain/webapps/django/lib/python2.6/django/db/models/sql/compiler.py" in execute_sql
  727.         cursor.execute(sql, params)
File "/home/robain/webapps/django/lib/python2.6/django/db/backends/util.py" in execute
  15.             return self.cursor.execute(sql, params)
File "/home/robain/webapps/django/lib/python2.6/django/db/backends/postgresql_psycopg2/base.py" in execute
  44.             return self.cursor.execute(query, args)

Exception Type: IntegrityError at /tempManage/addCT/13/34/
Exception Value: duplicate key value violates unique constraint "tempManage_childtemplate_previewPath_key"

我认为密钥的自动增量与实例 ID 不同步（根据其他帖子猜测），但我不确定如何修复它。任何帮助将非常感激！

编辑：询问模型，这是错误产生的模型。然而它已经运行了一段时间没有任何问题，所以它不太可能是在模型定义中引起的......

类 ChildTemplate(models.Model):

def get_CTswf_path(self, filename):
    return os.path.join('swf', 'Company_' + str(self.father.company.id), "FT_" + str(self.father.id), 'CT_' + str(self.id), filename)

father = models.ForeignKey('FatherTemplate', unique=False, verbose_name='Father', blank=True, null=True)
childName = models.CharField(max_length=20, blank=False, verbose_name='Child Name')
location = models.ForeignKey(Location, unique=False, blank=True, null=True)
company = models.ForeignKey(Company, unique=False, blank=True, null=True)
isCorporate = models.BooleanField(blank=False, verbose_name='Corporate')
templatePath = models.FileField(upload_to=get_CTswf_path, verbose_name='Path', blank=True, null=True)
previewPath = models.CharField(max_length=200, blank=True, unique=True)
#migrateTest = models.BooleanField()

def __unicode__(self):
    return self.childName

我之前在加载数据库备份时就遇到过这种情况。不知道为什么 postgres 没有正确更新序列 - 可能遇到了我没有看到的错误 - 但我使用的解决方案是检查主键字段中的最大值，然后从（手动）附加到它的序列，以将该序列放在正确的位置。

您可以从命令行客户端列出数据库中的所有序列（psql) with \ds。可能有一个名字类似tempManage_childtemplate_previewPath_id_seq.

像这样的东西应该有效。在手动更改数据库之前先备份它！

SELECT max(id) FROM <model_table>;
SELECT * FROM tempManage_childtemplate_previewPath_id_seq;

ALTER SEQUENCE tempManage_childtemplate_previewPath_id_seq RESTART WITH <result of above>;

刚刚意识到，您可能还想查看序列中已有的内容，因此我也在上面添加了一个选择。查看last_value entry.