在我的数据库中保存数据的最有效结构是什么？

Question

我正在尝试创建允许用户将项目保存到播放列表的功能，并且用户可以拥有多个播放列表。每个项目也可以保存到多个播放列表中。表示此数据的最佳方式是什么？有多个表，外键可以链接它们，还是只有一个平面表？

多个表

class Playlist(models.Model):
    playlist = models.CharField('Playlist', max_length = 2000, null=True, blank=True)
    def __unicode__(self):
        return self.playlist

class Video(models.Model):
    video_url = models.URLField('Link to video', max_length = 200, null=True, blank=True)
    video_tag = models.CharField('Video ID', max_length = 2000, null=True, blank=True)
    def __unicode__(self):
        return self.video_url

class UserPlaylist(models.Model):
    profile = models.ForeignKey(User)
    playlist = models.ForeignKey(Playlist)
    def __unicode__(self):
        return unicode(self.playlist)

class Videoplaylist(models.Model):
    video = models.ForeignKey(Video)
    playlist = models.ForeignKey(UserPlaylist)
    def __unicode__(self):
        return unicode(self.playlist)

1表

class Everything(models.Model):
    profile = models.ForeignKey(User)
    playlist = models.CharField('Playlist', max_length = 2000, null=True, blank=True)
    platform = models.CharField('Platform', max_length = 2000, null=True, blank=True)
    video = models.CharField('VideoID', max_length = 2000, null=True, blank=True)
    def __unicode__(self):
        return u'%s %s %s %s' % (self.profile, self.playlist, self.platform, self.video)

Answer 1

实体之间有两个主要关系：

• 播放列表 - ＆gt;用户，多对一
• 视频 - ＆gt; PlayList，多对多

基于以上所述，您应该以这样的方式安排数据：

class User():
    name = CharField()
    # other user info

class Video():
    name = CharField()
    # othter video info

class Playlist():
    user = ForeigenKey(User)
    name = CharField()

class PlaylistVideo():
    plist = ForeigenKey(Playlist)
    video = ForeigenKey(Video)

# When a user adds a video to one of his playlist
def add_video_to_playlist(user_name, playlist_name, video_name)
    user = User.objects.get(name=user_name)
    plist = Playlist.objects.get(user=user, name=playlist_name)

    video = Video.objects.get(name=video_name)
    plv = PlaylistVideo(plist=plist,video=video)
    plv.save()

# To get the content of a user's some playlist:
def get_playlist_content(user_name, playlist_names):
    user = User.objects.get(name=user_name)
    plist = Playlist.objects.get(user=user, name=playlist_name)

    return [plv.video for plv in PlaylistVideo.objects.filter(plist=plist)]