Django -- about Managers, django -- Managers

Django -- about Managers, django -- Managers
Default managers

If you use objecm Manager objects, take note that the first Manager Django encounters (in the order in which they're defined in the model) has a special status. django interprets the first Manager defined in a class as the "default" Manager, and several parts of Django (including dumpdata) will use that Manager exclusively for that model. as a result, it's a good idea to be careful in your choice of default manager in order to avoid a situation where overriding get_queryset () results in an inability to retrieve objects you 'd like to work.

I started to write two managers to determine whether the manager is private or not, and found that the display in admin becomes a File that can only be private:

Class PrivateFileManager (models. manager): def get_queryset (self): return super (PrivateFileManager, self ). get_queryset (). filter (public = True) class PublicFileManager (models. manager): def get_queryset (self): return super (PublicFileManager, self ). get_queryset (). fileter (public = False) class File (models. model): file = models. fileField (upload_to = 'medias') public = models. booleanField (default = True) # has default project = models. foreignKey (Project, related_name = "projects") tag = models. manyToManyField (Tag, related_name = "tags") uploader = models. foreignKey (User, related_name = "users") group = models. manyToManyField (Group, related_name = "groups") temp_delect = models. booleanField (default = False) # has default desc = models. textField (blank = True, null = True) upload_date = models. dateTimeField (auto_now_add = True) change_date = models. dateTimeField (auto_now = True) # Managers blow: privateFiles = PrivateFileManager () publicFiles = PublicFileManager () def _ unicode _ (self): return self. file. name class Meta: permissions = ("can_edit_file", "file editable"), ("can_list_file", "file list visible"), ("can_delete_file ", "can delete files"), ("can_download_file", "can download files "),)

Then I carefully read the document and found the beginning of the article, which means that the first manager defined will be used as the default manager .... I decisively added an ALL, which can be correctly displayed now. The Code is as follows:

<Span style = "color: # ff0000;"> class AllFileManager (models. manager): def get_queryset (self): return super (AllFileManager, self ). get_queryset (). all () </span> class PrivateFileManager (models. manager): def get_queryset (self): return super (PrivateFileManager, self ). get_queryset (). filter (public = True) class PublicFileManager (models. manager): def get_queryset (self): return super (PublicFileManager, self ). get_queryset (). fileter (public = False) class File (models. model): file = models. fileField (upload_to = 'medias') public = models. booleanField (default = True) # has default project = models. foreignKey (Project, related_name = "projects") tag = models. manyToManyField (Tag, related_name = "tags") uploader = models. foreignKey (User, related_name = "users") group = models. manyToManyField (Group, related_name = "groups") temp_delect = models. booleanField (default = False) # has default desc = models. textField (blank = True, null = True) upload_date = models. dateTimeField (auto_now_add = True) change_date = models. dateTimeField (auto_now = True) # Managers blow: <span style = "color: # ff0000;"> allFiles = AllFileManager () </span> privateFiles = PrivateFileManager () publicFiles = PublicFileManager () def _ unicode _ (self): return self. file. name class Meta: permissions = ("can_edit_file", "file editable"), ("can_list_file", "file list visible"), ("can_delete_file ", "can delete files"), ("can_download_file", "can download files "),)

That's all.