Python - Django - ORM 實例（二）
阿新 • • 發佈：2019-04-26
cut 獲得 put con 修改 thead 不存在 技術分享 cts
在 app01/models.py 中添加 Book 類對象表
from django.db import models
# Create your models here.
# 出版社
class Publisher(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
name = models.CharField(max_length=64, null=False, unique=True)
# 書籍
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")
然後執行命令更新到數據庫中
[email protected] > makemigrations [email protected] > migrate
在 Book 表中添加 3 條數據
展示書籍列表：
創建 book_list.html：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>書籍列表</title>
</head>
<body>
<table border="1">
<thead>
<tr>
<th>id</th>
<th>書名</th>
<th>出版社</th>
</tr>
</thead>
<tbody>
{% for book in book_list %}
<tr>
<td>{{ book.id }}</td>
<td>{{ book.title }}</td>
<td>{{ book.publisher.name }}</td>
</tr>
{% endfor %}
</tbody>
</table>
</body>
</html>
這裏的 book.publisher 獲取到的是 Publisher 對象，因為 publisher 關聯了 Publisher 對象
在 app01/views.py 中添加 book_list 函數
from django.shortcuts import render, redirect, HttpResponse
from app01 import models
# 展示出版社列表
def publisher_list(request):
# 去數據庫查出所有的出版社，填充到 html 中，返回給用戶
ret = models.Publisher.objects.all().order_by("id") # order_by("id") 通過 id 進行排序
return render(request, "publisher_list.html", {"publisher_list": ret})
# 添加新的出版社
def add_publisher(request):
# 如果是 POST 請求，就獲取用戶填寫的數據
if request.method == "POST":
new_publisher = request.POST.get("publisher_name")
# 獲得數據後去數據庫中新增一條數據
models.Publisher.objects.create(name=new_publisher)
# 添加成功後進行跳轉
return redirect("/publisher_list/")
# 用戶來到該界面返回的 html 頁面
return render(request, "add_publisher.html")
# 刪除出版社
def del_publisher(request):
# 從 GET 請求的參數中拿到要刪除的 id 值
del_id = request.GET.get(‘id‘)
# 如果取到 id 值，就去數據庫中刪除該 id 的數據
if del_id:
# 根據 id 查找數據，並刪除
del_obj = models.Publisher.objects.get(id=del_id).delete()
# 刪除後返回頁面
return redirect("/publisher_list/")
else:
return HttpResponse("要刪除的數據不存在！")
# 編輯出版社
def edit_publisher(request):
# 獲取 POST 發來的數據，並更新到數據庫中
if request.method == "POST":
# 獲取 POST 傳送來的 id 值和出版社
edit_id = request.POST.get(‘id‘)
new_name = request.POST.get(‘publisher_name‘)
# 根據 id 取得出版社
publisher = models.Publisher.objects.get(id=edit_id)
publisher.name = new_name
publisher.save() # 把修改的結果提交到數據庫
return redirect("/publisher_list/") # 跳轉到列表頁面
# 從 GET 請求中取得 id 值
publisher_id = request.GET.get(‘id‘)
if publisher_id:
# 獲取當前編輯的出版社對象
publisher_obj = models.Publisher.objects.get(id=publisher_id)
return render(request, "edit_publisher.html", {"publisher": publisher_obj})
else:
return HttpResponse("編輯的出版社不存在！")
# 展示書籍列表
def book_list(request):
# 去數據庫中查詢所有書籍
all_book = models.Book.objects.all()
# 渲染數據
return render(request, "book_list.html", {"book_list": all_book})
在 mysite0/urls.py 中添加對應關系
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r‘^publisher_list/‘, views.publisher_list),
url(r‘^add_publisher/‘, views.add_publisher),
url(r‘^del_publisher/‘, views.del_publisher),
url(r‘^edit_publisher/‘, views.edit_publisher),
url(r‘^book_list/‘, views.book_list),
]
運行結果：
添加書籍：
修改 book_list.html：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>書籍列表</title>
</head>
<body>
<table border="1">
<thead>
<tr>
<th>id</th>
<th>書名</th>
<th>出版社</th>
</tr>
</thead>
<tbody>
{% for book in book_list %}
<tr>
<td>{{ book.id }}</td>
<td>{{ book.title }}</td>
<td>{{ book.publisher.name }}</td>
</tr>
{% endfor %}
</tbody>
</table>
<a href="/add_book/">添加書籍</a>
</body>
</html>
創建 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="/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>
在 app01/views.py 中添加 add_book 函數
from django.shortcuts import render, redirect, HttpResponse
from app01 import models
# 展示出版社列表
def publisher_list(request):
# 去數據庫查出所有的出版社，填充到 html 中，返回給用戶
ret = models.Publisher.objects.all().order_by("id") # order_by("id") 通過 id 進行排序
return render(request, "publisher_list.html", {"publisher_list": ret})
# 添加新的出版社
def add_publisher(request):
# 如果是 POST 請求，就獲取用戶填寫的數據
if request.method == "POST":
new_publisher = request.POST.get("publisher_name")
# 獲得數據後去數據庫中新增一條數據
models.Publisher.objects.create(name=new_publisher)
# 添加成功後進行跳轉
return redirect("/publisher_list/")
# 用戶來到該界面返回的 html 頁面
return render(request, "add_publisher.html")
# 刪除出版社
def del_publisher(request):
# 從 GET 請求的參數中拿到要刪除的 id 值
del_id = request.GET.get(‘id‘)
# 如果取到 id 值，就去數據庫中刪除該 id 的數據
if del_id:
# 根據 id 查找數據，並刪除
del_obj = models.Publisher.objects.get(id=del_id).delete()
# 刪除後返回頁面
return redirect("/publisher_list/")
else:
return HttpResponse("要刪除的數據不存在！")
# 編輯出版社
def edit_publisher(request):
# 獲取 POST 發來的數據，並更新到數據庫中
if request.method == "POST":
# 獲取 POST 傳送來的 id 值和出版社
edit_id = request.POST.get(‘id‘)
new_name = request.POST.get(‘publisher_name‘)
# 根據 id 取得出版社
publisher = models.Publisher.objects.get(id=edit_id)
publisher.name = new_name
publisher.save() # 把修改的結果提交到數據庫
return redirect("/publisher_list/") # 跳轉到列表頁面
# 從 GET 請求中取得 id 值
publisher_id = request.GET.get(‘id‘)
if publisher_id:
# 獲取當前編輯的出版社對象
publisher_obj = models.Publisher.objects.get(id=publisher_id)
return render(request, "edit_publisher.html", {"publisher": publisher_obj})
else:
return HttpResponse("編輯的出版社不存在！")
# 展示書籍列表
def book_list(request):
# 去數據庫中查詢所有書籍
all_book = models.Book.objects.all()
print(all_book)
# 渲染數據
return render(request, "book_list.html", {"book_list": 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")
# 去數據庫中創建數據
models.Book.objects.create(title=new_title, publisher_id=new_publisher_id)
return redirect("/book_list/")
# 去數據庫取得出版社數據展示在頁面上以供用戶選擇
publishers = models.Publisher.objects.all()
return render(request, "add_book.html", {"publisher_list": publishers})
在 mysite0/urls.py 中添加對應關系
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r‘^admin/‘, admin.site.urls),
url(r‘^publisher_list/‘, views.publisher_list),
url(r‘^add_publisher/‘, views.add_publisher),
url(r‘^del_publisher/‘, views.del_publisher),
url(r‘^edit_publisher/‘, views.edit_publisher),
url(r‘^book_list/‘, views.book_list),
url(r‘^add_book/‘, views.add_book),
]
運行結果：
點擊“添加書籍”
點擊“提交”
刪除書籍：
修改 book_list.html：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>書籍列表</title>
</head>
<body>
<table border="1">
<thead>
<tr>
<th>id</th>
<th>書名</th>
<th>出版社</th>
<th>操作</th>
</tr>
</thead>
<tbody>
{% for book in book_list %}
<tr>
<td>{{ book.id }}</td>
<td>{{ book.title }}</td>
<td>{{ book.publisher.name }}</td>
<td>
<a href="/del_book/?id={{ book.id }}">刪除</a>
</td>
</tr>
{% endfor %}
</tbody>
</table>
<a href="/add_book/">添加書籍</a>
</body>
</html>
在 app01/views.py 中添加 del_book 函數
from django.shortcuts import render, redirect, HttpResponse
from app01 import models
# 展示出版社列表
def publisher_list(request):
# 去數據庫查出所有的出版社，填充到 html 中，返回給用戶
ret = models.Publisher.objects.all().order_by("id") # order_by("id") 通過 id 進行排序
return render(request, "publisher_list.html", {"publisher_list": ret})
# 添加新的出版社
def add_publisher(request):
# 如果是 POST 請求，就獲取用戶填寫的數據
if request.method == "POST":
new_publisher = request.POST.get("publisher_name")
# 獲得數據後去數據庫中新增一條數據
models.Publisher.objects.create(name=new_publisher)
# 添加成功後進行跳轉
return redirect("/publisher_list/")
# 用戶來到該界面返回的 html 頁面
return render(request, "add_publisher.html")
# 刪除出版社
def del_publisher(request):
# 從 GET 請求的參數中拿到要刪除的 id 值
del_id = request.GET.get(‘id‘)
# 如果取到 id 值，就去數據庫中刪除該 id 的數據
if del_id:
# 根據 id 查找數據，並刪除
del_obj = models.Publisher.objects.get(id=del_id).delete()
# 刪除後返回頁面
return redirect("/publisher_list/")
else:
return HttpResponse("要刪除的數據不存在！")
# 編輯出版社
def edit_publisher(request):
# 獲取 POST 發來的數據，並更新到數據庫中
if request.method == "POST":
# 獲取 POST 傳送來的 id 值和出版社
edit_id = request.POST.get(‘id‘)
new_name = request.POST.get(‘publisher_name‘)
# 根據 id 取得出版社
publisher = models.Publisher.objects.get(id=edit_id)
publisher.name = new_name
publisher.save() # 把修改的結果提交到數據庫
return redirect("/publisher_list/") # 跳轉到列表頁面
# 從 GET 請求中取得 id 值
publisher_id = request.GET.get(‘id‘)
if publisher_id:
# 獲取當前編輯的出版社對象
publisher_obj = models.Publisher.objects.get(id=publisher_id)
return render(request, "edit_publisher.html", {"publisher": publisher_obj})
else:
return HttpResponse("編輯的出版社不存在！")
# 展示書籍列表
def book_list(request):
# 去數據庫中查詢所有書籍
all_book = models.Book.objects.all()
print(all_book)
# 渲染數據
return render(request, "book_list.html", {"book_list": 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")
# 去數據庫中創建數據
models.Book.objects.create(title=new_title, publisher_id=new_publisher_id)
return redirect("/book_list/")
# 去數據庫取得出版社數據展示在頁面上以供用戶選擇
publishers = models.Publisher.objects.all()
return render(request, "add_book.html", {"publisher_list": publishers})
# 刪除書籍
def del_book(request):
# 從 URL 中獲取要刪除的書籍的 id
del_id = request.GET.get("id")
# 去數據庫中刪除指定 id 的書籍
models.Book.objects.get(id=del_id).delete()
# 跳轉到書籍列表頁面
return redirect("/book_list/")
在 mysite0/urls.py 中添加對應關系
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r‘^admin/‘, admin.site.urls),
url(r‘^publisher_list/‘, views.publisher_list),
url(r‘^add_publisher/‘, views.add_publisher),
url(r‘^del_publisher/‘, views.del_publisher),
url(r‘^edit_publisher/‘, views.edit_publisher),
url(r‘^book_list/‘, views.book_list),
url(r‘^add_book/‘, views.add_book),
url(r‘^del_book/‘, views.del_book),
]
運行結果：
刪除“PHP”
頁面閃了一下，PHP 就被刪除了
Python - Django - ORM 實例（二）