关系如下

from django.db import models  
class Blog(models.Model):  
   name = models.CharField(max_length=100)  
   tagline = models.TextField()  
   def __str__(self):              
       return self.name  

class Author(models.Model):  
   name = models.CharField(max_length=50)  
   email = models.EmailField()  
   def __str__(self):             
       return self.name  

class Entry(models.Model):  
   blog = models.ForeignKey(Blog)  
   headline = models.CharField(max_length=255)  
   body_text = models.TextField()  
   authors = models.ManyToManyField(Author)  
   def __str__(self):              
      return self.headline

Entry中有Blog和Author的外键,如果要在Entry中读取blog和author的数据很容易:


entry = Entry.objects.all()  
for e in entry:  
    blog = e.blog  
    author = e.authors

要在Blog和Author中读取Entry也可以：

blog = Blog.objects.all()  
entry = blog.entry_set.all()  

author = Author.objects.all()  
entry = author.entry_set.all()