from django.db import models# Create your models here.class One(models.Model):  oname = models.CharField(max_length=20,null=True)  oage = models.CharField(max_length=20,null=True)  odate = models.DateField(null=True)class Two(models.Model):# 設置一對一關系，是通過將表中的字段設置為主鍵完成的# on_delete=models.CASCADE 當父表中的某一條數據刪除的時候  # 相關字表中的數據也會被刪除  tsub = models.OneToOneField(One,on_delete=models.CASCADE,primary_key=True)  tfond = models.CharField(max_length=20,null=True)  tdes = models.CharField(max_length=200,null=True)

import pymysqlpymysql.install_as_MySQLdb()

python manage.py makemigrationspython manage.py migrate

from django.shortcuts import renderfrom .models import One,Two# Create your views here.def index(request):  o1 = One.objects.create(oname='張三',oage=11,odate='2011-11-11')  o2 = One.objects.create(oname='張三2',oage=12,odate='2012-12-12')  t1 = Two.objects.create(tsub=o1,tfond='o1',tdes='我喜歡o1')  t2 = Two.objects.create(tsub=o2,tfond='o2',tdes='我喜歡o2')  return render(request,'index.html')

def select(request):  t1 = Two.objects.get(tsub__oname = '張三')  return render(request,'index.html',{'t1':t1})

from django.db import models# Create your models here.class People(models.Model):  name = models.CharField(max_length=50)  card_num = models.IntegerField(default=0)class Card(models.Model):  number = models.CharField(max_length=20)  person = models.ForeignKey(People,on_delete=models.CASCADE)  source = models.CharField(max_length=50)

from django.contrib import adminfrom django.urls import pathfrom myApp import viewsurlpatterns = [  path('admin/', admin.site.urls),  path('add/',views.add),  path('select/',views.select),]

from django.shortcuts import renderfrom .models import People,Cardfrom django.http import HttpResponse# Create your views here.# 添加數據def add(request):  # p1 = People.objects.create(name='小王',card_num = 4)  # p2 = People.objects.create(name='老王', card_num=40)  #  # c1 = Card(number='101',source = '中國銀行',person = p1)  # c2 = Card(number='102', source='中國農行', person=p1)  # c3 = Card(number='110', source='中國建行', person=p1)  # c1.save()  # c2.save()  # c3.save()  #  # c4 = Card(number='201', source='河南鄭州美容美發', person=p2)  # c5 = Card(number='202', source='鄭州交通一卡通', person=p2)  # c6 = Card(number='203', source='鄭州逍遙鎮胡辣湯', person=p2)  # c7 = Card(number='204', source='鄭州惠濟四附院', person=p2)  #  # c4.save()  # c5.save()  # c6.save()  # c7.save()  return HttpResponse('添加成功')def select(request):  # 查找number=203的人  c1 = Card.objects.get(number='203')  print(c1.person.name)  # 查找id為3對應的人  c2 = Card.objects.get(id=3)  print(c2.person.name)  # 查找c2的所有卡  result = c2.person.card_set.all()  print(result)  for res in result:    print(res.source)  # 查找名字為老王的所有卡種  result = People.objects.get(name='老王')  for card in result.card_set.all():    print(card.source)  return HttpResponse('查詢成功')

from django.db import models# Create your models here.class Publication(models.Model):  pname = models.CharField(max_length=200)  paddress = models.CharField(max_length=200)class Book(models.Model):  bname = models.CharField(max_length=200)  bauthor = models.CharField(max_length=200)  publication = models.ManyToManyField(Publication)

from django.shortcuts import renderfrom .models import Publication,Bookfrom django.http import HttpResponse# Create your views here.def add(request):  # p1 = Publication(pname='大象出版社',paddress='河南',)  # p2 = Publication(pname='北京出版社',paddress='北京')  # p3 = Publication(pname='清華出版社',paddress='河北')  # p1.save()  # p2.save()  # p3.save()  #  # b1 = Book(bname='海底兩萬里',bauthor='趙四')  # b2 = Book(bname='遮天',bauthor='辰東')  # b3 = Book(bname='童年', bauthor='xxxx')  # b4 = Book(bname='在人間', bauthor='yyyy')  # b5 = Book(bname='我的大學', bauthor='張飛')  # b6 = Book(bname='湯姆索亞歷險記', bauthor='趙六兒')  # b1.save()  # b2.save()  # b3.save()  # b4.save()  # b5.save()  # b6.save()  #  # b1.publication.add(p1,p2,p3)  # b2.publication.add(p1,p2)  # b3.publication.add(p1,p3)  # b4.publication.add(p2,p3)  # b5.publication.add(p3)  # 多對多關系，兩個表不直接產生聯系，而是將兩個表之間的關系記錄在中間表上  # 中間表不需要創建，會自動生成  return HttpResponse('添加成功')def select(request):  # 通過書籍查找對應的出版社  b1 = Book.objects.get(bname='童年')  # 獲取出版童年的所有出版社  b1_publication = b1.publication.all()  for pub in b1_publication:    print(pub.pname)    print(pub.paddress)  p1 = Publication.objects.get(pname = '清華出版社')  all_book = p1.book_set.all()  print('------------------')  for book in all_book:    print(book.bname)    print(book.bauthor)  return HttpResponse('查找成功')