ORM 查询操作
修改 views.py 文件
from django.shortcuts import render, HttpResponse
from app01 import models
from app01.models import Book,Author,Publisher
def data_oper(req):
# 获取 book 表 id 为2的价格
book = models.Book.objects.filter(id=2).values("price")
print(book)
# 获取 author 表 id 为 1 的名字
authors = models.Author.objects.filter(id=1)[0]
print(authors)
# 获取 author 表 id 为 3 名字
author1 = models.Author.objects.get(id=3)
print(author1)
# 以 id 为倒序排列输出记录
author2 = models.Author.objects.order_by("-id")
print(author2)
return HttpResponse("Hello world")
反向查找
from django.shortcuts import render, HttpResponse
from app01 import models
from app01.models import Book,Author,Publisher
def data_oper(req):
# 查找 Publish name 是 广东工业出版社 的 书籍
obj=models.Publisher.objects.filter(name="广东工业出版社")[0]
print(obj.book_set.all().values("title"))
return HttpResponse("Hello world")
def data_oper(req):
# 查找书籍名为 K8S 的出版社名字
print(models.Publisher.objects.filter(book__title="K8S").values("name"))
# 查找出版社名为 广东工业出版社 的书籍名字
print(models.Book.objects.filter(publisher__name="广东工业出版社").values("title"))
return HttpResponse("Hello world")
from django.shortcuts import render, HttpResponse
from app01 import models
from app01.models import Book,Author,Publisher
def data_oper(req):
# 查询所有出版社城市为 广州 的书名
ret = models.Book.objects.filter(publisher__city='广州').values('title')
print(ret)
# 查询对应操作的sql语句
print(ret.query)
return HttpResponse("Hello world")
ORM 删除操作
修改 views.py 文件
from django.shortcuts import render, HttpResponse
from app01 import models
from app01.models import Book,Author,Publisher
def data_oper(req):
# 多对多的情况下，删除 book id 为1，author id 大于0的记录
book = models.Book.objects.filter(id=2)[0]
authors = models.Author.objects.filter(id__gt=0)
book.authors.remove(*authors)
# 删除单条记录，删除 book 表中 id 为 1 的记录
models.Book.objects.filter(id=1).delete()
return HttpResponse("Hello world")
ORM 更新操作
修改 views.py 文件
from django.shortcuts import render, HttpResponse
from app01 import models
from app01.models import Book,Author,Publisher
def data_oper(req):
# 把 author id 为 3 的 name 改为 katy
author = models.Author.objects.get(id=3)
author.name = "katy"
author.save()
return HttpResponse("Hello world")