Django DurationField 默认值
Django DurationField default
我想将默认值从 django 1.8 传递到 DurationField。根据文档,它应该是 datetime.timedelta
from datetime import timedelta
pause = DurationField(default=timedelta(minutes=20))
但是在 makemigrations 上它说:
ValueError: Cannot serialize: datetime.timedelta(0, 1200)
There are some values Django cannot serialize into migration files.
好的。也许我们应该传递整数?
pause = DurationField(default=int(timedelta(minutes=20).total_seconds()))
或:
pause = DurationField(default=20*60)
makemigrations 运行正常,但在创建对象时我看到:
for obj in self.query.objs
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/sql/compiler.py", line 920, in <listcomp>
for obj in self.query.objs
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/sql/compiler.py", line 918, in <listcomp>
) for f in fields
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 710, in get_db_prep_save
prepared=False)
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1683, in get_db_prep_value
return value.total_seconds() * 1000000
AttributeError: 'int' object has no attribute 'total_seconds'
所以它需要 timedelta?
你稍微搞错了顺序:
pause = DurationField(default=int(timedelta(minutes=20).total_seconds()))
如前所述,整数没有 total_seconds()
属性。相反,它是一个 instance method of timedelta
.
默认值应该是时间增量。这是 Django 中的一个错误,将在 1.8.1 版本中修复。
参见:https://code.djangoproject.com/ticket/24566
所以pause = DurationField(default=timedelta(minutes=20))
应该适用于 1.8.1 版本。
我想将默认值从 django 1.8 传递到 DurationField。根据文档,它应该是 datetime.timedelta
from datetime import timedelta
pause = DurationField(default=timedelta(minutes=20))
但是在 makemigrations 上它说:
ValueError: Cannot serialize: datetime.timedelta(0, 1200)
There are some values Django cannot serialize into migration files.
好的。也许我们应该传递整数?
pause = DurationField(default=int(timedelta(minutes=20).total_seconds()))
或:
pause = DurationField(default=20*60)
makemigrations 运行正常,但在创建对象时我看到:
for obj in self.query.objs
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/sql/compiler.py", line 920, in <listcomp>
for obj in self.query.objs
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/sql/compiler.py", line 918, in <listcomp>
) for f in fields
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 710, in get_db_prep_save
prepared=False)
File "/home/web/django_env/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1683, in get_db_prep_value
return value.total_seconds() * 1000000
AttributeError: 'int' object has no attribute 'total_seconds'
所以它需要 timedelta?
你稍微搞错了顺序:
pause = DurationField(default=int(timedelta(minutes=20).total_seconds()))
如前所述,整数没有 total_seconds()
属性。相反,它是一个 instance method of timedelta
.
默认值应该是时间增量。这是 Django 中的一个错误,将在 1.8.1 版本中修复。 参见:https://code.djangoproject.com/ticket/24566
所以pause = DurationField(default=timedelta(minutes=20))
应该适用于 1.8.1 版本。