多对对建表和queryset机制

# Create your views here.

from app_01.models import Book
from app_01 import models

from datetime import datetime
from django.http import HttpResponse
from django.shortcuts import render


def date_op(req):

    obj_set = models.Book.objects.filter(id=3)

    #  迭代器（性能）
    if obj_set.iterator():
        pass

    #    -- for循环

    # obj_set = models.Book.objects.filter(id=3)
    # for obj in obj_set:
    #     print(obj.title)
    #
    # obj_set.update(title='js')
    # for obj in obj_set:
    #     print(obj.title)

    # 修改
    # models.Book.objects.filter(id=3).update(price=30)

    # 删除
    # models.Book.objects.filter(id=2).delete()

    # models.Book_To_Author.objects.create(
    #     book_id=1,
    #     author_id=2,
    # )


    # dic1 = {"title": "", "price": 35, "color": "yellow"}
    # Book.objects.create(**dic1)

    # Book.objects.create(
    #     title="li漂流记",
    #     price=1,
    #     color="yellow",
    #
    #     publisher_id=4,
    # )

    # book = models.Book.objects.filter(id=2)
    # price = book.values("price")

    # #   某些书绑定某些作者
    # book = models.Book.objects.filter(id=2)[0]
    # authors = models.Author.objects.filter(id_gt=2)
    # # 绑定关系
    # book.author.add(*authors)
    # # 取消关系
    # book.author.remove(*authors)

    return HttpResponse("ok")


def index(request):
    class Person:
        def __init__(self, name, age):
            self.name = name
            self.age = age

    s1 = 'abc123'
    s2 = [11, 'bb', 33]
    s3 = {'username': 'li', 'sex': 'M', 'height': '172'}
    s4 = datetime.now()
    s5 = Person('yuan', '18')
    s6 = [1, 2]
    s7 = '<a href="#">跳转</a>'

    return render(request, 'index.html', {'obj': s7})


def login(req):
    if req.method == "POST":
        return HttpResponse('ok')

    name = "hello"
    num = 90

    return render(req, "login.html", locals())


def ordered(req):
    return render(req, 'ordered.html')


def shopping_car(req):
    return render(req, 'shopping_car.html')