5、django操作表一对多实战

发布时间：2020-07-19 14:17:12 来源：网络阅读：377 作者：yht_1990 栏目：编程语言

表结构
5、django操作表一对多实战
一、入口url设置
D:\mysite\mysite\urls.py

from django.contrib import admin
from django.urls import path,include

urlpatterns = [
    path('polls/',include('polls.urls')),
    path('admin/', admin.site.urls),
]

二、polls应用url设置
D:\mysite\polls\urls.py

from django.urls import path

from . import views
app_name = 'polls'
urlpatterns = [

    #出版社相关的对应关系
        #出版社列表页
    path('publisher_list/', views.published_list,name='published_list'),
        #添加出版社
    path('add_publisher/', views.add_publisher,name='add_publisher'),
        #删除出版社
    path('delete_ublisher/', views.delete_publisher,name='delete_publisher'),
        #编辑出版社
    path('edit_publisher/', views.edit_publisher,name='edit_publisher'),

    #书相关的对应关系
        #书籍列表页
    path('book_list/', views.book_list,name='book_list'),
        #添加书籍
    path('add_book/', views.add_book,name='add_book'),  
        #删除书籍
    path('delete_book/', views.delete_book,name='delete_book'),  
        #编辑书籍
    path('edit_book/', views.edit_book,name='edit_book'),  

]

三、modes配置
D:\mysite\polls\models.py

from django.db import models
#出版社
class Publisher(models.Model):
    id = models.AutoField(primary_key=True)  # 自增的ID主键
    #创建一个varchar(64)的唯一的不为空的字段
    name = models.CharField(max_length=64, null=False)

#书
class Book(models.Model):
    id = models.AutoField(primary_key=True)  # 自增的ID主键
    #创建一个varchar(64)的唯一的不为空的字段
    title = models.CharField(max_length=64, null=False, unique=True)
    #和出版社关联的外键字段
    publisher = models.ForeignKey(to="Publisher", on_delete=models.CASCADE)

#建建表
python manage.py makemigrations
python manage.py migrate

四静态文件设置

####################出版社html#########################
#出版社列表页D:\mysite\polls\templates\polls\publisher_list.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>出版社列表</title>
</head>
<body>

<a href="/polls/add_publisher/">添加新的出版社</a>

<table border="1">
    <thead>
        <tr>
            <th>序号</th>
            <th>ID</th>
            <th>出版社名称</th>
            <th>操作</th>
        </tr>
    </thead>
    <tbody>
        {% for publisher in publisher_list %}
            <tr>
                <td>{{ forloop.counter }}</td>
                <td>{{ publisher.id }}</td>
                <td>{{ publisher.name }}</td>
                <td>
                    <a href="/polls/delete_publisher/?id={{ publisher.id }}">删除</a>
                    <a href="/polls/edit_publisher/?id={{ publisher.id }}">编辑</a>
                </td>
            </tr>
        {% endfor %}
    </tbody>
</table>

</body>
</html>

#添加出版社列表页D:\mysite\polls\templates\polls\add_publisher.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加出版社</title>
</head>
<body>

<h2>添加出版社</h2>

<form action="{% url 'polls:add_publisher' %}" method="post">
    {% csrf_token %}
    <input type="text" name="publisher_name">
    <input type="submit" value="提交">
    <p >{{ error }}</p>
</form>

</body>
</html>

#编辑出版社列表页D:\mysite\polls\templates\polls\edit_publisher.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>编辑出版社</title>
</head>
<body>

<h2>编辑出版社</h2>

<form action="/polls/edit_publisher/" method="post">
    <input type="text" name="id" value="{{ publisher.id }}" >
    <input type="text" name="publisher_name" value="{{ publisher.name }}">
    <input type="submit" value="提交">
    <p >{{ error }}</p>
</form>

</body>
</html>

####################书籍html#########################
#书籍列表页D:\mysite\polls\templates\polls\book_list.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>书籍列表</title>
</head>
<body>

<h2>所有的书籍都在这里!</h2>
<a href="/polls/add_book/">添加书籍</a>

<table border="1">
    <thead>
        <tr>
            <th>id</th>
            <th>title</th>
            <th>publisher</th>
            <th>操作</th>
        </tr>
    </thead>
    <tbody>
        {% for i in all_book %}
            <tr>
            <td>{{ i.id }}</td>
            <td>{{ i.title }}</td>
            <td>{{ i.publisher.name }}</td>
            <td>
                <a href="/polls/delete_book/?id={{ i.id }}">删除</a>
                <a href="/polls/edit_book/?id={{ i.id }}">编辑</a>
            </td>
            </tr>
        {% endfor %}
    </tbody>
</table>
</body>
</html>

#添加书籍D:\mysite\polls\templates\polls\add_book.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加书籍</title>
</head>
<body>

<h2>添加书籍</h2>
<form action="/polls/add_book/" method="post">
    <p>
        书名:<input type="text" name="book_title">
    </p>
    <p>
        出版社:
        <select name="publisher" >
            {% for publisher in publisher_list %}
                <option value="{{ publisher.id }}">{{ publisher.name }}</option>
            {% endfor %}
        </select>
    </p>
    <p>
         <input type="submit" value="提交">
    </p>

</form>

</body>
</html>

#编辑书籍
D:\mysite\polls\templates\polls\edit_book.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>编辑书籍</title>
</head>
<body>

<h2>编辑书籍</h2>

<form action="/polls/edit_book/" method="post">
    <input type="hidden"  name="id" value="{{ book_obj.id }}">
    <p>
        书名:
        <input type="text" name="book_title" value="{{ book_obj.title }}">
    </p>
    <p>
        出版社:
        <select name="publisher">

            {% for publisher in publisher_list %}

                {% if book_obj.publisher_id == publisher.id %}
                    {#  当前书籍关联的出版社才默认选中#}
                    <option selected value="{{ publisher.id }}">{{ publisher.name }}</option>
                {% else %}
                    {# 其他的出版社不选中 #}
                    <option value="{{ publisher.id }}">{{ publisher.name }}</option>
                {% endif %}
            {% endfor %}

        </select>
    </p>
    <p>
        <input type="submit" value="提交">
    </p>
</form>

</body>
</html>

五、后端处理D:\mysite\polls\views.py

from django.shortcuts import render,redirect,ttpResponse
from .models import Question,Publisher
from polls import models

#出版社列表
def published_list(request):
    ret = Publisher.objects.all().order_by("id")
    return render(request,"polls/publisher_list.html",{"publisher_list": ret})

#添加新的出版社
def add_publisher(request):
    error_msg = ""
    #如果是POST请求,我就取到用户填写的数据
    print(request.method)
    if request.method == "POST":
        new_name = request.POST.get("publisher_name", None)
        if new_name:
            # 通过ORM去数据库里新建一条记录
            Publisher.objects.create(name=new_name)
            #引导用户访问出版社列表页,查看是否添加成功  --> 跳转
            return redirect("/polls/publisher_list/")
        else:
            error_msg = "出版社名字不能为空!"
    #用户第一次来,我给他返回一个用来填写的HTML页面
    return render(request, "polls/add_publisher.html", {"error": error_msg})

#删除出版社
def delete_publisher(request):
    print(request.GET)
    print("=" * 120)
    #删除指定的数据
    #1. 从GET请求的参数里面拿到将要删除的数据的ID值
    del_id = request.GET.get("id", None)  # 字典取值,娶不到默认为None
    #如果能取到id值
    if del_id:
        # 去数据库删除当前id值的数据
        #根据id值查找到数据
        del_obj = models.Publisher.objects.get(id=del_id)
        #删除
        del_obj.delete()
        #返回删除后的页面,跳转到出版社的列表页,查看删除是否成功
        return redirect("/polls/publisher_list/")
    else:
        return HttpResponse("要删除的数据不存在!")

#编辑出版社
def edit_publisher(request):
    #用户修改完出版社的名字,点击提交按钮,给我发来新的出版社名字
    if request.method == "POST":
        print(request.POST)
        #取新出版社名字
        edit_id = request.POST.get("id")
        new_name = request.POST.get("publisher_name")
        #更新出版社
        #根据id取到编辑的是哪个出版社
        edit_publisher = models.Publisher.objects.get(id=edit_id)
        edit_publisher.name = new_name
        edit_publisher.save()  # 把修改提交到数据库
        #跳转出版社列表页,查看是否修改成功
        return redirect("/polls/publisher_list/")
    #从GET请求的URL中取到id参数
    edit_id = request.GET.get("id")
    if edit_id:
        #获取到当前编辑的出版社对象
        publisher_obj = models.Publisher.objects.get(id=edit_id)
        return render(request, "polls/edit_publisher.html", {"publisher": publisher_obj})
    else:
        error_msg = "编辑的出版社不存在!"
        return HttpResponse("编辑的出版社不存在!")

#展示书的列表
def book_list(request):
    # 去数据库中查询所有的书籍
    all_book = models.Book.objects.all()
    #在HTML页面完成字符串替换(渲染数据)
    return render(request, "polls/book_list.html", {"all_book": all_book})

#添加书籍
def add_book(request):
    if request.method == "POST":
        new_title = request.POST.get("book_title")
        new_publisher_id = request.POST.get("publisher")
        #创建新书对象,自动提交
        models.Book.objects.create(title=new_title, publisher_id=new_publisher_id)
        #返回到书籍列表页
        return redirect("/polls/book_list/")

    #取到所有的出版社
    ret = models.Publisher.objects.all()
    return render(request, "polls/add_book.html", {"publisher_list": ret})

#删除书籍
def delete_book(request):
    #从URL里面获取要删除的书籍的id值
    delete_id = request.GET.get("id")  # 从URL里面取数据
    #去删除数据库中删除指定id的数据
    models.Book.objects.get(id=delete_id).delete()
    #返回书籍列表页面, 查看是否删除成功
    return redirect("/polls/book_list/")

#编辑书籍
def edit_book(request):
    if request.method == "POST":
        # 从提交的数据里面取,书名和书关联的出版社
        edit_id = request.POST.get("id")
        new_title = request.POST.get("book_title")
        new_publisher_id = request.POST.get("publisher")
        #更新
        edit_book_obj = models.Book.objects.get(id=edit_id)
        edit_book_obj.title = new_title  # 更新书名
        edit_book_obj.publisher_id = new_publisher_id  # 更新书籍关联的出版社
        #将修改提交到数据库
        edit_book_obj.save()
        #返回书籍列表页面,查看是否编辑成功
        return redirect("/polls/book_list/")

    #返回一个页面,让用户编辑书籍信息
    #取到编辑的书的id值
    edit_id = request.GET.get("id")
    #根据id去数据库中把具体的书籍对象拿到
    edit_book_obj = models.Book.objects.get(id=edit_id)
    ret = models.Publisher.objects.all()
    return render(
        request,
        "polls/edit_book.html",
        {"publisher_list": ret, "book_obj": edit_book_obj}
    )

访问出版社列表页
http://127.0.0.1:8000/polls/publisher_list/
5、django操作表一对多实战