Django模型:列的默认值 [英] Django models: default value for column
问题描述
我有以下 Django
型号代码:
status = models.PositiveIntegerField(default = 0b000)
comments_allowed = models.BooleanField(default = True) # whether comments are allowed to this post
但我预计会生成SQL,如
But I expected, it would generate SQL like
`status` integer NOT NULL default '4',
`comments_allowed` bool NOT NULL default TRUE
哪些没有发生,当我运行 manage.py sqlall appname
它会生成:
Which is not happening and when I run manage.py sqlall appname
it produces:
`status` integer UNSIGNED NOT NULL,
`comments_allowed` bool NOT NULL
深入 Django
的代码和谷歌搜索给了我什么,但詹姆斯·班纳特的评论说,默认
不会影响生成 SQL
,但Django管理员需要。即使如此,我如何获得期望的效果?
Delving into Django
's code and googling gave me nothing, but James Bennet's comment that default
is not assumed to affect generating SQL
, but needed for Django admin. Even if so, how do I get desired effect?
我的 Django
版本是1.3.0 final
My Django
version is 1.3.0 final
推荐答案
请注意,默认值
参数也可以使用可调用对象: https://docs.djangoproject.com/en/dev/ref/models/fields /#默认。这当然是一个不能在SQL中复制的行为!所以Django不可能为每种可能的情况生成SQL。它似乎是为了简单和一致,他们选择不为任何情况生成SQL。
Note that the default
parameter can also take a callable object: https://docs.djangoproject.com/en/dev/ref/models/fields/#default. That is certainly a behavior that cannot be reproduced in SQL! So it would not be possible for Django to generate SQL for every possible case. It looks like for the sake of simplicity and consistency they have chosen not to generate SQL for any case.
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