6、django操作表多對多實戰
阿新 • • 發佈：2019-04-28
dde tex img 信息 turn 自動轉換 nag body code 圖書管理系統表設計結構
author的id對應author_book的author_id
book的id對應author_book的book_id
#########orm工具設置
D:\mysite\polls\models.py
orm：對像關系映射，將Python語法自動轉換成sql語句
from django.db import models #書 class Book(models.Model): id = models.AutoField(primary_key=True) # 自增的ID主鍵 #創建一個varchar(64)的唯一的不為空的字段 title = models.CharField(max_length=64, null=False, unique=True) #和出版社關聯的外鍵字段 publisher = models.ForeignKey(to="Publisher", on_delete=models.CASCADE) #作者表 class Author(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=16, null=False, unique=True) #告訴ORM 我這張表和book表是多對多的關聯關系,ORM自動幫我生成了第三張表 book = models.ManyToManyField(to="Book") def __str__(self): return "<Author Object: {}>".format(self.name)
會生成三張表
polls_book表
polls_author表
polls_author_books表
#########主url設置
from django.contrib import admin
from django.urls import path,include
urlpatterns = [
path(‘polls/‘,include(‘polls.urls‘)),
path(‘admin/‘, admin.site.urls),
]#########應用url設置
D:\mysite\polls\urls.py
from django.urls import path from . import views app_name = ‘polls‘ urlpatterns = [ #書相關的對應關系 path(‘book_list/‘, views.book_list,name=‘book_list‘), path(‘add_book/‘, views.add_book,name=‘add_book‘), # 添加書籍 path(‘delete_book/‘, views.delete_book,name=‘delete_book‘), # 刪除書籍 path(‘edit_book/‘, views.edit_book,name=‘edit_book‘), # 編輯書籍 # 作者相關的對應關系 path(‘author_list/‘, views.author_list,name=‘author_list‘), # 展示作者 path(‘add_author/‘, views.add_author,name=‘add_author‘), # 添加作者 path(‘delete_author/‘, views.delete_author,name=‘delete_author‘), # 刪除作者 path(‘edit_author/‘, views.edit_author,name=‘edit_author‘), # 編輯作者 ]
#########後端函數
D:\mysite\polls\views.py
from django.shortcuts import render,redirect,HttpResponse from .models import Question,Publisher from polls import models #展示書的列表 def book_list(request): # 去數據庫中查詢所有的書籍 all_book = models.Book.objects.all() #在HTML頁面完成字符串替換(渲染數據) return render(request, "polls/book_list.html", {"all_book": all_book}) #添加書籍 def add_book(request): if request.method == "POST": new_title = request.POST.get("book_title") new_publisher_id = request.POST.get("publisher") #創建新書對象,自動提交 models.Book.objects.create(title=new_title, publisher_id=new_publisher_id) #返回到書籍列表頁 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}) #刪除書籍 def delete_book(request): #從URL裏面獲取要刪除的書籍的id值 delete_id = request.GET.get("id") # 從URL裏面取數據 #去刪除數據庫中刪除指定id的數據 models.Book.objects.get(id=delete_id).delete() #返回書籍列表頁面, 查看是否刪除成功 return redirect("/polls/book_list/") #編輯書籍 def edit_book(request): if request.method == "POST": # 從提交的數據裏面取,書名和書關聯的出版社 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 # 更新書名 edit_book_obj.publisher_id = new_publisher_id # 更新書籍關聯的出版社 #將修改提交到數據庫 edit_book_obj.save() #返回書籍列表頁面,查看是否編輯成功 return redirect("/polls/book_list/") #返回一個頁面,讓用戶編輯書籍信息 #取到編輯的書的id值 edit_id = request.GET.get("id") #根據id去數據庫中把具體的書籍對象拿到 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} ) #作者列表頁 def author_list(request): # 查詢所有的作者 all_author = models.Author.objects.all() return render(request, "polls/author_list.html", {"author_list": all_author}) #添加作者 def add_author(request): if request.method == "POST": print("in post...") #取到提交的數據 new_author_name = request.POST.get("author_name") #post提交的數據是多個值的時候一定會要用getlist,如多選的checkbox和多選的select books = request.POST.getlist("books") #創建作者 new_author_obj = models.Author.objects.create(name=new_author_name) #把新作者和書籍建立對應關系,自動提交 new_author_obj.book.set(books) #跳轉到作者列表頁面,查看是否添加成功! return redirect("/polls/author_list/") #查詢所有的書籍 ret = models.Book.objects.all() return render(request, "polls/add_author.html", {"book_list": ret}) #刪除作者 def delete_author(request): # 從URL裏面取到要刪除的作者id delete_id = request.GET.get("id") #根據ID值取到要刪除的作者對象,直接刪除 #1. 去作者表把作者刪了 #2. 去作者和書的關聯表,把對應的關聯記錄刪除了 models.Author.objects.get(id=delete_id).delete() #返回作者列表頁面 return redirect("/polls/author_list/") #編輯作者 def edit_author(request): # 如果編輯完提交數據過來 if request.method == "POST": # 拿到提交過來的編輯後的數據 edit_author_id = request.POST.get("author_id") new_author_name = request.POST.get("author_name") # 拿到編輯後作者關聯的書籍信息 new_books = request.POST.getlist("books") # 根據ID找到當前編輯的作者對象 edit_author_obj = models.Author.objects.get(id=edit_author_id) # 更新作者的名字 edit_author_obj.name = new_author_name # 更新作者關聯的書的對應關系 edit_author_obj.book.set(new_books) # 將修改提交到數據庫 edit_author_obj.save() # 返回作者列表頁,查看是否編輯成功 return redirect("/polls/author_list/") # 從URL裏面取要編輯的作者的id信息 edit_id = request.GET.get("id") # 找到要編輯的作者對象 edit_author_obj = models.Author.objects.get(id=edit_id) # 查詢所有的書籍對象 ret = models.Book.objects.all() return render(request, "polls/edit_author.html", {"book_list": ret, "author": edit_author_obj})
#########靜態html文件
#book列表頁
D:\mysite\polls\templates\polls\book_list.htmll
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>書籍列表</title>
</head>
<body>
<h1>所有的書籍都在這裏!</h1>
<a href="/polls/add_book/">添加書籍</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 }}">刪除</a>
<a href="/polls/edit_book/?id={{ i.id }}">編輯</a>
</td>
</tr>
{% endfor %}
</tbody>
</table>
</body>
</html>##book添加頁
D:\mysite\polls\templates\polls\add_book.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>添加書籍</title>
</head>
<body>
<h1>添加書籍</h1>
<form action="/polls/add_book/" method="post">
<p>
書名:<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>#book編輯頁
D:\mysite\polls\templates\polls\edit_book.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>編輯書籍</title>
</head>
<body>
<h1>編輯書籍</h1>
<form action="/polls/edit_book/" method="post">
<input type="hidden" name="id" value="{{ book_obj.id }}">
<p>
書名:
<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 %}
{# 當前書籍關聯的出版社才默認選中#}
<option selected value="{{ publisher.id }}">{{ publisher.name }}</option>
{% else %}
{# 其他的出版社不選中 #}
<option value="{{ publisher.id }}">{{ publisher.name }}</option>
{% endif %}
{% endfor %}
</select>
</p>
<p>
<input type="submit" value="提交">
</p>
</form>
</body>
</html>#作者列表頁
D:\mysite\polls\templates\polls\author_list.htm
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>作者列表</title>
</head>
<body>
<a href="/polls/add_author/">添加新的作者</a>
<h1>所有的作者</h1>
<table border="1">
<thead>
<tr>
<th>#</th>
<th>ID</th>
<th>名字</th>
<th>作品</th>
<th>操作</th>
</tr>
</thead>
<tbody>
{% for author in author_list %}
<tr>
<td>{{ forloop.counter }}</td>
<td>{{ author.id }}</td>
<td>{{ author.name }}</td>
<td>
{% for book in author.book.all %}
{{ book.title }}?
{% endfor %}
</td>
<td>
<a href="/polls/delete_author/?id={{ author.id }}">刪除</a>
<a href="/polls/edit_author/?id={{ author.id }}">編輯</a>
</td>
</tr>
{% endfor %}
</tbody>
</table>
</body>
</html>#作者添加頁
D:\mysite\polls\templates\polls\add_author.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>添加作者</title>
</head>
<body>
<h1>添加作者</h1>
<form action="/polls/add_author/" method="post">
<p>
作者姓名:<input type="text" name="author_name">
</p>
<p>
作品:
<select multiple name="books">
{% for book in book_list %}
<option value="{{ book.id }}">{{ book.title }}</option>
{% endfor %}
</select>
</p>
<p>
<input type="submit" value="提交">
</p>
</form>
</body>
</html>#作者編輯頁
D:\mysite\polls\templates\polls\edit_author.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>編輯作者</title>
</head>
<body>
<h1>編輯作者</h1>
<form action="/polls/edit_author/" method="post">
<input type="text" name="author_id" value="{{ author.id }}" style="display: none">
<p>
作者姓名:<input type="text" name="author_name" value="{{ author.name }}">
</p>
<p>
作品:
<select multiple name="books">
{% for book in book_list %}
{# 如果當前這本書 在 當前作者關聯的所有書 裏面 #}
{% if book in author.book.all %}
<option selected value="{{ book.id }}">{{ book.title }}</option>
{% else %}
<option value="{{ book.id }}">{{ book.title }}</option>{% endif %}
{% endfor %}
</select>
</p>
<p>
<input type="submit" value="提交">
</p>
</form>
</body>
</html>模板裏author.book.all的含義
#web展示
作者列表頁
作者添加頁
作者編輯頁
6、django操作表多對多實戰