实现一对多表查询功能

项目代码：

models.py

from django.db import models# Create your models here.class Classes(models.Model):    """    班级表,男    """    titile = models.CharField(max_length=32)    m = models.ManyToManyField("Teachers")class Teachers(models.Model):    """    老师表，女    """    name = models.CharField (max_length=32)"""cid_id  tid_id 1    1 1    2 6    1 1000  1000"""# class C2T(models.Model):#     cid = models.ForeignKey(Classes)#     tid = models.ForeignKey(Teachers)class Student(models.Model):    username = models.CharField(max_length=32)    age = models.IntegerField()    gender = models.BooleanField()    cs = models.ForeignKey(Classes)

urls.py

"""django_one URL ConfigurationThe `urlpatterns` list routes URLs to views. For more information please see:    https://docs.djangoproject.com/en/1.10/topics/http/urls/Examples:Function views    1. Add an import:  from my_app import views    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')Class-based views    1. Add an import:  from other_app.views import Home    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')Including another URLconf    1. Import the include() function: from django.conf.urls import url, include    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))"""from django.conf.urls import urlfrom django.contrib import adminfrom app01.views import classesfrom app01.views import studentsurlpatterns = [    url(r'^admin/', admin.site.urls),    url(r'^get_classes.html$', classes.get_classes),    url(r'^add_classes.html$', classes.add_classes),    url(r'^del_classes.html$', classes.del_classes),    url(r'^edit_classes.html$', classes.edit_classes),    url(r'^get_students.html$', students.get_students),    url(r'^add_students.html$', students.add_students),    url(r'^del_students.html$', students.del_students),    url(r'^edit_students.html$', students.edit_students),]

students.py

from django.shortcuts import renderfrom django.shortcuts import redirectfrom app01 import modelsdef get_students(request):    stu_list = models.Student.objects.all()    # for i in stu_list:    #     print(i.id,i.username,i.age,i.cs.id,i.cs.titile)    return render(request,'get_students.html',{
   'stu_list':stu_list})def add_students(request):    if request.method == 'GET':        cs_list = models.Classes.objects.all()        return render(request, 'add_students.html', {
   'cs_list': cs_list})    elif request.method == 'POST':        u = request.POST.get('username')        a = request.POST.get('age')        g = request.POST.get('gender')        c = request.POST.get('cs')        models.Student.objects.create(            username=u,            age=a,            gender=g,            cs_id=c,        )    return redirect('/get_students.html')def del_students(request):    nid = request.GET.get('nid')    models.Student.objects.filter(id=nid).delete()    return redirect('get_students.html')def edit_students(request):    if request.method == "GET":        nid = request.GET.get('nid')        obj = models.Student.objects.filter(id=nid).first()        cls_list = models.Classes.objects.all()        return render(request, 'edit_students.html',{
   'obj': obj,'cls_list': cls_list})    elif request.method == "POST":        u = request.GET.get('username')        a = request.GET.get('age')        g = request.GET.get('gender')        c = request.GET.get('cs')        models.Student.objects.filter(nid=id).update(            username=u,            age=a,            gender=g,            cs_id=c,        )        return redirect('/get_students.html')

get_students.html

    
         
     
    
      添加
     
     
    
      
                {
    % for row in stu_list %}            
                {
    % if row.gender %}                    
                {
    % else %}                    
                {
    % endif %}                
        {
    % endfor %}        
               
                
                     
ID
                     
姓名
                     
年龄
                     
性别
                     
班级
                     
操作
                
               
               
        
                         
{
   { row.id }}
                         
{
   { row.username }}
                         
{
   { row.age }}
         
男
         
女
         
{
   { row.cs.titile }}
                         
                    删除                    |                    编辑                
                    
       
          
     

add_students.html

    
         
添加用户
     
          {
    % csrf_token %}    
      
    
      
    
      
        男:        女:    
    
      
                 {
    % for foo in cs_list %}            {
   { foo.titile }}         {
    % endfor %}            
    
      
     

edit_students.html

    
         
     
          {
    % csrf_token %}    
      
    
      
    
      
        {
    % if obj.gender %}            男:            女:        {
    % else %}            男:            女:        {
    % endif %}    
    
      
                    {
    % for foo in cls_list %}                {
    % if obj.cs_id == foo.id %}                    {
   { foo.titile }}                {
    % else %}                    {
   { foo.titile }}                {
    % endif %}            {
    % endfor %}            {