正向查詢

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

def query(request):
    # ###############基於對象查詢（子查詢）##############
    # 一對多查詢 book-->publish
    #正向查詢：
    # 查詢python這本書的出版社的email郵箱.
    python_obj = models.Book.objects.filter(title =‘python‘).first()
    print(python_obj.publish.email)
    return HttpResponse(‘ OK‘)

# ###############基於對象查詢（子查詢）##############
                    # 正向查詢按字段查詢
# 一對多查詢 book----------------------->publish
#                  <----------------------
                    #反向查詢 book_set.all()





反向查詢

反向查詢#查詢五道口出版社的書籍名稱 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 操作復習苑浩