django--關於Managers,django--Managers
Default managers
If you use custom 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 with.
開始寫了兩個判斷是否私密的manager,然後發現admin裡面的顯示變成了只能顯示私密的File:
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", "能編輯檔案"), ("can_list_file", "能看檔案清單"), ("can_delete_file", "能刪除檔案"), ("can_download_file", "能下載檔案"), )
然後再仔細看了一下文檔,發現了文章開頭的那段話,大概意思就是定義的第一個manager將會作為預設manager....我果斷加了一個ALL,現在可以正確顯示了,代碼如下:
<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", "能編輯檔案"), ("can_list_file", "能看檔案清單"), ("can_delete_file", "能刪除檔案"), ("can_download_file", "能下載檔案"), )
That's all.