本文整理汇总了Python中django.db.models.deletion.SET_NULL属性的典型用法代码示例。如果您正苦于以下问题：Python deletion.SET_NULL属性的具体用法？Python deletion.SET_NULL怎么用？Python deletion.SET_NULL使用的例子？那么恭喜您, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在类django.db.models.deletion的用法示例。
在下文中一共展示了deletion.SET_NULL属性的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: _check_on_delete
# 需要导入模块: from django.db.models import deletion [as 别名]
# 或者: from django.db.models.deletion import SET_NULL [as 别名]
def _check_on_delete(self):
on_delete = getattr(self.rel, 'on_delete', None)
if on_delete == SET_NULL and not self.null:
return [
checks.Error(
'Field specifies on_delete=SET_NULL, but cannot be null.',
hint='Set null=True argument on the field, or change the on_delete rule.',
obj=self,
id='fields.E320',
)
]
elif on_delete == SET_DEFAULT and not self.has_default():
return [
checks.Error(
'Field specifies on_delete=SET_DEFAULT, but has no default value.',
hint='Set a default value, or change the on_delete rule.',
obj=self,
id='fields.E321',
)
]
else:
return [] 示例2: _check_on_delete
# 需要导入模块: from django.db.models import deletion [as 别名]
# 或者: from django.db.models.deletion import SET_NULL [as 别名]
def _check_on_delete(self):
on_delete = getattr(self.remote_field, 'on_delete', None)
if on_delete == SET_NULL and not self.null:
return [
checks.Error(
'Field specifies on_delete=SET_NULL, but cannot be null.',
hint='Set null=True argument on the field, or change the on_delete rule.',
obj=self,
id='fields.E320',
)
]
elif on_delete == SET_DEFAULT and not self.has_default():
return [
checks.Error(
'Field specifies on_delete=SET_DEFAULT, but has no default value.',
hint='Set a default value, or change the on_delete rule.',
obj=self,
id='fields.E321',
)
]
else:
return []