django 外键model的互相读取方法
先设定一个关系模型如下：
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
上面的数据关系很明晰,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()
下面通过entry使blog和author互相读取，比如要知道一个blog的Author只需如下：
blogs = Blog.objects.all() for blog in blogs: if blog.name== “我们想要查询的博客的name” author = blog. entry_set.authors
要查询一个author的所有blog如下：
authors = Author.objects.all() blogs = [] for author in authors: if author.name== “我们想要查询的Author的name” for entry in author.entry_set.all(): blogs.append(entry. blog)
以上这篇django 外键model的互相读取方法就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持【听图阁-专注于Python设计】。