ORM 操作复习苑浩

 正向查询

from django.shortcuts import render,HttpResponse
from app01 import models
# Create your views here.

def query(request):
    # ###############基于对象查询（子查询）##############
    # 一对多查询 book-->publish
    #正向查询：
    # 查询python这本书的出版社的email邮箱.
    python_obj = models.Book.objects.filter(title =‘python‘).first()
    print(python_obj.publish.email)
    return HttpResponse(‘ OK‘)

# ###############基于对象查询（子查询）##############
                    # 正向查询按字段查询
# 一对多查询 book----------------------->publish
#                  <----------------------
                    #反向查询 book_set.all()





反向查询

反向查询#查询五道口出版社的书籍名称 pub_obj =models.Publish.objects.filter(name =‘五道口出版社‘).last()
 for obj  in pub_obj.book_set.all():
     print(obj.title)

 return HttpResponse(‘ OK‘)

ORM 操作复习苑浩

原文：https://www.cnblogs.com/mengbin0546/p/9125358.html