DjangoORM多对多案例！

一、数据准备

from django.db import models

# Create your models here.
class Boy(models.Model):
    nickname = models.CharField(max_length=32)
    username = models.CharField(max_length=32)
    password = models.CharField(max_length=63)

class Girl(models.Model):
    nickname = models.CharField(max_length=32)
    username = models.CharField(max_length=32)
    password = models.CharField(max_length=63)

class B2G(models.Model):
    b = models.ForeignKey(Boy, on_delete=models.CASCADE)
    g = models.ForeignKey(Girl, on_delete=models.CASCADE)
数据表
from django.http import HttpResponse

from app01 import models
def init_models(request):
    # 管理员验证，保证数据安全性
    # 略
    girls = [
        models.Girl(nickname='娜美', username='namei', password='123'),
        models.Girl(nickname='老幺', username='laoyao', password='123'),
        models.Girl(nickname='女帝', username='nvdi', password='123')
    ]
    models.Girl.objects.bulk_create(girls, 10)
    boys = [
        models.Boy(nickname='路飞', username='lufei', password='123'),
        models.Boy(nickname='柒禾', username='qihe', password='123'),
        models.Boy(nickname='索隆', username='zoro', password='123')
    ]
    models.Boy.objects.bulk_create(boys, 10)
    love = [
        models.B2G(b_id='1', g_id='1'),
        models.B2G(b_id='1', g_id='3'),
        models.B2G(b_id='2', g_id='2'),
        models.B2G(b_id='3', g_id='2'),
        models.B2G(b_id='2', g_id='3'),
    ]
    models.B2G.objects.bulk_create(love, 10)
    return HttpResponse('添加数据成功')
数据填充

二、前端页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/app01/myLogin.html" method="POST">
        {% csrf_token %}
        <p>用户名：<input type="text" name="username"></p>
        <p>密码: <input type="password" name="password"></p>
        <p>
            性别：
            男 <input type="radio" name="gender" value="1">
            女 <input type="radio" name="gender" value="2">
        </p>
        <input type="submit" value="提交">{{ msg }}
        <p><input type="checkbox" name="rmb" value="True">一个免登陆</p>
    </form>
</body>
</html>
myLogin.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    {% include 'user_header.html' %}
    <h3>异性列表</h3>
    <a href="/app01/others.html">查看和我有关系的异性</a>
    <ul>
        {% for row in user_list %}
            <li>{{ row.nickname }}</li>
        {% endfor %}
    </ul>
</body>
</html>
index.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
{% include 'user_header.html' %}
<p>其他异性</p>
    <ul>
        {% for row in user_list %}
            {% if row.g__nickname %}
                <li>{{ row.g__nickname }}</li>
            {% else %}
                <li>{{ row.b__nickname }}</li>
            {% endif %}
        {% endfor %}
    </ul>
</body>
</html>
others.html
<h1>当前用户:{{ request.session.user_info.nickname }}</h1>
<h1>{{ request.session.user_info }}</h1>
<a href="/logout.html">注销</a>
user_header.html

三、路由系统

"""day74 URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/3.1/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.urls import include, path
    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.contrib import admin
from django.urls import path, re_path, include
from day74 import views
import app01
urlpatterns = [
    # path('admin/', admin.site.urls),
    # path('test/', views.test),
    # path('test1/', views.test_ajax),
    # re_path(r'^login$', views.login),#显示ajax登录页面
    # re_path(r'^login_ajax_check$', views.login_ajax_check),#显示ajax登录校验
    path('app01/', include('app01.urls')),
]
主urls
"""day74 URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/3.1/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.urls import include, path
    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.urls import path
from app01.views import account, love, init_models

urlpatterns = [
    path('myLogin.html', account.myLogin),
    path('others.html', love.others),
    path('index.html', love.index),
    path('init_models.html', init_models.init_models)
]
app01.urls

四、视图函数

from django.http import HttpResponse
from django.shortcuts import render, redirect

from app01 import models

def myLogin(request):
    if request.method == 'GET':
        return render(request, 'myLogin.html')
    else:
        user = request.POST.get('username')
        pwd = request.POST.get('password')
        gender = request.POST.get('gender')
        rmb = request.POST.get('rmb')
        print(user, pwd, gender)
        # 获取用户对象
        if gender == '1':
            obj = models.Boy.objects.filter(username=user, password=pwd).first()
        else:
            obj = models.Girl.objects.filter(username=user, password=pwd).first()

        if not obj:
            # 没有登录成功
            return render(request, 'myLogin.html', {'msg': '用户名或者密码错误'})
        else:
            request.session['user_info'] = {'user_id': obj.id, 'gender': gender, 'username': user, 'nickname': obj.nickname}
            return redirect('/app01/index.html')
account
from django.shortcuts import redirect, render

from app01 import models

def index(request):
    if not request.session.get('user_info'):
        return redirect('/login.html')
    else:
        gender = request.session.get('user_info').get('gender')
        if gender == '1':
            user_list = models.Girl.objects.all()
        else:
            user_list = models.Boy.objects.all()
        return render(request, 'index.html', {'user_list': user_list})

def others(request):
    current_user_id = request.session.get('user_info').get('user_id')
    gender = request.session.get('user_info').get('gender')

    if gender == '1':
        user_list = models.B2G.objects.filter(b_id=current_user_id).values('g__nickname')
    else:
        user_list = models.B2G.objects.filter(g_id=current_user_id).values('b__nickname')
    print('result', user_list)
    return render(request, 'others.html', {'user_list': user_list})
love
from django.http import HttpResponse

from app01 import models
def init_models(request):
    # 管理员验证，保证数据安全性
    # 略
    girls = [
        models.Girl(nickname='娜美', username='namei', password='123'),
        models.Girl(nickname='老幺', username='laoyao', password='123'),
        models.Girl(nickname='女帝', username='nvdi', password='123')
    ]
    models.Girl.objects.bulk_create(girls, 10)
    boys = [
        models.Boy(nickname='路飞', username='lufei', password='123'),
        models.Boy(nickname='柒禾', username='qihe', password='123'),
        models.Boy(nickname='索隆', username='zoro', password='123')
    ]
    models.Boy.objects.bulk_create(boys, 10)
    love = [
        models.B2G(b_id='1', g_id='1'),
        models.B2G(b_id='1', g_id='3'),
        models.B2G(b_id='2', g_id='2'),
        models.B2G(b_id='3', g_id='2'),
        models.B2G(b_id='2', g_id='3'),
    ]
    models.B2G.objects.bulk_create(love, 10)
    return HttpResponse('添加数据成功')
一的数据填充
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原文地址：https://www.cnblogs.com/854594834-YT/p/13849018.html