Django 自定義用戶 UUID 重復（緩存？）

Question

我正在使用帶有自定義 UUID 和自定義用戶管理器的自定義用戶模型的 Django：

class CustomUser(AbstractUser):
    id = models.UUIDField(primary_key=True, default=generate_id(), editable=False)
# ...

如您所見，我沒有使用default=uuid4() 。 相反，我自己創建了一個函數，它使用 uuid() 生成自定義 id，也使用時間戳：

from datetime import datetime as dt
from uuid import uuid1, uuid3, uuid4

def generate_id():
    timestamp = str(dt.timestamp(dt.now()))
    return uuid3(uuid4(),timestamp)

現在，如果我打開交互式 shell： python manage.py shell並多次調用我的函數，這就是我得到的：

>>> generate_id()
UUID('bd8279f1-9b4b-3d7d-8932-f9e725f17045')
>>> generate_id()
UUID('0c2ec2ad-b062-3915-a9e9-22842c6f5ea2')
>>> generate_id()
UUID('2289202b-f252-3b27-bcae-cd44825bf4e0')
>>> generate_id()
UUID('88676ea9-4902-36ac-857d-929cb133089c')
>>> generate_id()
UUID('4a18b33e-12f0-3803-8ff0-0c4f0d1c849c')

但是當我嘗試創建 2 個用戶時：

from users.models import CustomUser
>>> one = CustomUser.objects.create_user(email='hhh@jaja.com',password='JJlsaks16112')
>>> two = CustomUser.objects.create_user(email='ttth@jija.com',password='JJlsaks16112')


Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/mysql/base.py", line 73, in execute
    return self.cursor.execute(query, args)
  File "/usr/local/lib/python3.8/site-packages/MySQLdb/cursors.py", line 206, in execute
    res = self._query(query)
  File "/usr/local/lib/python3.8/site-packages/MySQLdb/cursors.py", line 319, in _query
    db.query(q)
  File "/usr/local/lib/python3.8/site-packages/MySQLdb/connections.py", line 259, in query
    _mysql.connection.query(self, query)
MySQLdb._exceptions.IntegrityError: (1062, "Duplicate entry 'b448f583acfb31b7955926689b60f28a' for key 'PRIMARY'")

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/foodbook24-api/users/models.py", line 23, in create_user
    user.save()
  File "/usr/local/lib/python3.8/site-packages/django/contrib/auth/base_user.py", line 67, in save
    super().save(*args, **kwargs)
  File "/usr/local/lib/python3.8/site-packages/django/db/models/base.py", line 753, in save
    self.save_base(using=using, force_insert=force_insert,
  File "/usr/local/lib/python3.8/site-packages/django/db/models/base.py", line 790, in save_base
    updated = self._save_table(
  File "/usr/local/lib/python3.8/site-packages/django/db/models/base.py", line 895, in _save_table
    results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
  File "/usr/local/lib/python3.8/site-packages/django/db/models/base.py", line 933, in _do_insert
    return manager._insert(
  File "/usr/local/lib/python3.8/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/usr/local/lib/python3.8/site-packages/django/db/models/query.py", line 1254, in _insert
    return query.get_compiler(using=using).execute_sql(returning_fields)
  File "/usr/local/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1397, in execute_sql
    cursor.execute(sql, params)
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 98, in execute
    return super().execute(sql, params)
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.8/site-packages/django/db/utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.8/site-packages/django/db/backends/mysql/base.py", line 73, in execute
    return self.cursor.execute(query, args)
  File "/usr/local/lib/python3.8/site-packages/MySQLdb/cursors.py", line 206, in execute
    res = self._query(query)
  File "/usr/local/lib/python3.8/site-packages/MySQLdb/cursors.py", line 319, in _query
    db.query(q)
  File "/usr/local/lib/python3.8/site-packages/MySQLdb/connections.py", line 259, in query
    _mysql.connection.query(self, query)
django.db.utils.IntegrityError: (1062, "Duplicate entry 'b448f583acfb31b7955926689b60f28a' for key 'PRIMARY'")

如果我進入數據庫並修改我的第一個自定義用戶的 ID，我可以創建第二個用戶，但正如您從下面的屏幕截圖中看到的，ID 不會更改！

我猜是緩存問題。 任何人都知道我該如何解決它？ （可能保留我的自定義 UUID 函數）謝謝。

Answer 1

您正在調用該函數，因此default=…參數 [Django-doc]將設置為響應的結果，而不是函數，因此實際上，每次生成對象時，它都會使用該結果。

因此，您應該傳遞對callable的引用，而不是結果：

class CustomUser(AbstractUser):
    #                                           parenthesis ↓
    id = models.UUIDField(primary_key=True, default=generate_id, editable=False)