old_contents: from django.db import models
  
  class Classify(models.Model):
      name = models.CharField(max_length=20)
  
      def __str__(self):
          return self.name
  
  class Tag(models.Model):
      name = models.CharField(max_length=20)
  
      def __str__(self):
          return self.name
      
  class Article(models.Model):
      title = models.CharField(max_length=50)
      content = models.TextField()
      created_time = models.DateTimeField(auto_now=True)
      classify = models.ForeignKey(Classify)
      tag = models.ForeignKey(Tag)
      hits = models.IntegerField(default=0)
  
      class Meta:
          ordering = ['-created_time']
      def __str__(self):
          return self.title
  
  class Album(models.Model):
      name = models.CharField(max_length=50)
      cover = models.ImageField(upload_to='images/covers/%Y/%m/%d', null=True, blank=True)
  
      def __str__(self):
          return self.name    
  
  class Photo(models.Model):
      photo = models.ImageField(upload_to='images/%Y/%m/%d')
      description = models.CharField(max_length=255, null=True)
      created_time = models.DateTimeField(auto_now=True, null=True)
      album = models.ForeignKey(Album)
  
      class Meta:
          ordering = ['-created_time']
      def __str__(self):
          return self.description
  
  class Music(models.Model):
      title =  models.CharField(max_length=50)
      mp3 = models.FileField(upload_to='music/%Y/%m/%d')
      created_time = models.DateTimeField(auto_now=True, null=True)
  
      class Meta:
          ordering = ['-created_time']
      def __str__(self):
          return self.title
  
new_contents: from django.db import models
  
  
  class Classify(models.Model):
      name = models.CharField(max_length=20)
  
      def __str__(self):
          return self.name
  
  
  class Tag(models.Model):
      name = models.CharField(max_length=20)
  
      def __str__(self):
          return self.name
  
  
  class Article(models.Model):
      title = models.CharField(max_length=50)
      content = models.TextField()
      created_time = models.DateTimeField(auto_now=True)
      classify = models.ForeignKey(Classify)
      tag = models.ForeignKey(Tag)
      hits = models.IntegerField(default=0)
  
      class Meta:
          ordering = ['-created_time']
  
      def __str__(self):
          return self.title
  
  
  class Album(models.Model):
      name = models.CharField(max_length=50)
      cover = models.ImageField(upload_to='images/covers/%Y/%m/%d', null=True, blank=True)
  
      def __str__(self):
          return self.name    
  
  
  class Photo(models.Model):
      photo = models.ImageField(upload_to='images/%Y/%m/%d')
      description = models.CharField(max_length=255, null=True)
      created_time = models.DateTimeField(auto_now=True, null=True)
      album = models.ForeignKey(Album)
  
      class Meta:
          ordering = ['-created_time']
  
      def __str__(self):
          return self.description
  
  
  class Music(models.Model):
      title =  models.CharField(max_length=50)
      mp3 = models.FileField(upload_to='music/%Y/%m/%d')
      created_time = models.DateTimeField(auto_now=True, null=True)
  
      class Meta:
          ordering = ['-created_time']
  
      def __str__(self):
          return self.title
  
subject: add more suggested blank lines