old_contents: from django.contrib import admin
  
  from .models import Channel, Thumbnail, Video
  
  
  class VideoInline(admin.StackedInline):
      extra = 1
      model = Video
  
  
  class ThumbnailInline(admin.TabularInline):
      extra = 1
      model = Thumbnail
  
  
  class ChannelAdmin(admin.ModelAdmin):
      fieldsets = (
          (None, {'fields': ('username',)}),
          ('Relations', {'fields': ('idol', 'group')}),
      )
      inlines = [VideoInline]
      list_display = ['username', 'idol', 'group']
      list_select_related = True
  
      raw_id_fields = ('idol', 'group',)
      autocomplete_lookup_fields = {'fk': ['idol', 'group']}
  admin.site.register(Channel, ChannelAdmin)
  
  
  class VideoAdmin(admin.ModelAdmin):
      fieldsets = (
          (None, {'fields': ('channel', 'ytid')}),
          (None, {'fields': ('title', 'description', 'published', 'duration')}),
      )
      inlines = [ThumbnailInline]
      list_display = ['title', 'channel', 'published', 'duration', 'ytid']
      list_select_related = True
  
      raw_id_fields = ('channel',)
      autocomplete_lookup_fields = {'fk': ['channel']}
  admin.site.register(Video, VideoAdmin)
  
new_contents: from django.contrib import admin
  
  from .models import Channel, Thumbnail, Video
  
  
  class VideoInline(admin.StackedInline):
      extra = 1
      model = Video
  
  
  class ThumbnailInline(admin.TabularInline):
      extra = 1
      model = Thumbnail
  
  
  class ChannelAdmin(admin.ModelAdmin):
      fieldsets = (
          (None, {'fields': ('username', 'ytid')}),
          ('Relations', {'fields': ('idol', 'group')}),
      )
      inlines = [VideoInline]
      list_display = ['username', 'idol', 'group']
      list_select_related = True
  
      raw_id_fields = ('idol', 'group',)
      autocomplete_lookup_fields = {'fk': ['idol', 'group']}
  admin.site.register(Channel, ChannelAdmin)
  
  
  class VideoAdmin(admin.ModelAdmin):
      fieldsets = (
          (None, {'fields': ('channel', 'ytid')}),
          (None, {'fields': ('title', 'description', 'published', 'duration')}),
      )
      inlines = [ThumbnailInline]
      list_display = ['title', 'channel', 'published', 'duration', 'ytid']
      list_select_related = True
  
      raw_id_fields = ('channel',)
      autocomplete_lookup_fields = {'fk': ['channel']}
  admin.site.register(Video, VideoAdmin)
  
subject: Add ytid to the ChannelAdmin.