When stale content types are detected in theremove_stale_contenttypescommand, there’s now a list of related objects such asauth.Permissions that will also be deleted. Previously, only the content types were li
当使用unique()或db_index的列来检索单个对象时,有两个原因。首先,由于底层数据库索引的存在,查询的速度会更快。另外,如果多个对象与查找对象相匹配,查询的运行速度可能会慢很多;在列上有一个唯一约束保证这种情况永远不会发生。 因此使用示例 Weblog 模型: ...
unique_together = (("department", "number", "title"),) I have no problems saving Department or Course objects. I also have no problems when I add edit_inline=True in the department field as long as at least one other field has core=True. It's only if I fail to add a core=True...
也是有的, 就是不适用于跨多张表,因为连表本身就耗性能,连表越多,越慢# # user_list就是 [obj, obj, obj]# user_list = models.UserInfo.objects.all().select_related('ud', 'ut')# print(user_list.query)# """# SELECT `userinfo`.`id`, `userinfo`.`name`, `userinfo`.`pwd`, `userinf...
>>> Fruit.objects.values_list('name', flat=True) <QuerySet ['Apple', 'Pear']> 1. 2. 3. 4. 5. 6. 7. 8. 9. unique:如果设置为True,这个字段的值必须在整个表中保持唯一。 自动设置主键 默认情况下,Django 给每个模型一个自动递增的主键,其类型在AppConfig.default_auto_field中指定,或者在DE...
In django python, I am able to overwrite the save_related function (when save_as = True) so the instance I am trying to copy is saved and copied properly. When I save, though, I want other objects in other tables linked by an ID in the sql database that should be copied when the...
movie_list = movies.objects. all ().order_by( "-like_num" )[: 3 ] return movie_list users = user.objects. all () all_user = {} for user in users: rates = user.ratemovie_set. all () rate = {} # 用户有给电影打分 ...
The admin interface for related objects and the ordering interface need some tighter integration. Currently, anything that can be ordered goes in the right sidebar of the admin change form, with no relation to the actual input fields for those objects. The adding, removing, editing and ordering...
(User, through='TeamAdmin', related_name='admin_teams', related_query_name='admin_teams') class User(AbstractUser): class Meta: db_table = '"users"' username = None email = models.EmailField(blank=False, unique=True) objects = UserManager() USERNAME_FIELD = 'email' REQUIRED...
<6> unique:数据唯一 <7> verbose_name Admin中字段的显示名称 <8> validator_list:有效性检查。非有效产生 django.core.validators.ValidationError 错误 <9> db_column,db_index 如果为真将为此字段创建索引 <10>choices:一个用来选择值的2维元组。第一个值是实际存储的值,第二个用来方便进行选择。 如SEX_...