Question

我有这些相关模型，其中一个有自定义管理器

class Device(Model):
    name = CharField()

class DeviceSettingManager(Manager):
    use_for_related_fields = True

class Setting(Model):
    name = CharField()
    value = CharField()
    device = ForeignKey(Device, related_name='settings')

    objects = DeviceSettingManager

但是当我运行Django shell时，我看到正在使用的“RelatedManager”管理器

>>> d = Device.objects.all()[0]
>>> type(d.settings)
django.db.models.fields.related.create_foreign_related_manager..RelatedManager

如何让DeviceSettingManager用于设备的设置？

Answer 1

不要介意在管理员上调用type()的结果，DeviceSettingManager实际上正在使用中。您可以通过执行以下操作来检查：

class DeviceSettingManager(models.Manager):
    use_for_related_fields = True

    def manager_status(self):
        print("Device Setting Manager is Active")

并致电：

>>> d = Device.objects.all()[0]
>>> d.settings.manager_status()
Device Setting Manager is Active

即使您明确地将经理传递给相关对象，例如：

>> d.settings(manager="settings_objects")

当然：

class Setting(Model):
    name = CharField()
    value = CharField()
    device = ForeignKey(Device, related_name='settings')

    settings_objects = DeviceSettingManager() # Notice the parenthesis

经理的class仍会显示为：django.db.models.fields.related_descriptors.create_reverse_many_to_one_manager.<locals>.RelatedManager

别介意class名称。

如何为相关对象创建自定义管理器？

1 个答案: