django基于orm实践

说明

这篇文章介绍了django中简单的类视图单表操作，本次开始进行基于orm的一对多，一对一，多对多的实践
关于orm的具体介绍，可以查看这篇文章的笔记

一对多

model

class Book(models.Model):
    title = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    pub_date = models.DateField()
    # 关联出版社一对多，意思就是一个出版社可以有印刷多本书
    publish = models.ForeignKey("Publish", on_delete=models.CASCADE, default=None)

# 出版商
class Publish(models.Model):
    name = models.CharField(max_length=32)
    city = models.CharField(max_length=64)
    email = models.EmailField()

生效

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python manage.py makemigrations TestModel# 让 Django 知道我们在我们的模型有一些变更
python manage.py migrate TestModel   # 创建表

view&html

这里的配置和book的代码一模一样
运行代码新增出版商的数据

改造book

forms/book，加入了publish

class BookForm(forms.ModelForm):
    class Meta:
        model = Book
        fields = ['title', 'price', 'publish']

    # 你可以在这里添加额外的验证逻辑
    def clean_title(self):
        title = self.cleaned_data['title']
        if not title:
            raise forms.ValidationError("Title is required.")
        return title

书籍的index.html 引用出版商

1	{{ book.publish.name }}-

后续的增删改查，不用改动任何代码

多对多&一对一

model

一对一

新建作者和作者详情表，也就是一个作者一个作者详情

class Author(models.Model):
    name = models.CharField(max_length=32)
    age = models.SmallIntegerField()
    # 一对一，意思为一个作者对应一个作者详情
    au_detail = models.OneToOneField("AuthorDetail", on_delete=models.CASCADE)

class AuthorDetail(models.Model):
    gender_choices = (
        (0, "女"),
        (1, "男"),
        (2, "保密"),
    )
    gender = models.SmallIntegerField(choices=gender_choices)
    tel = models.CharField(max_length=32)
    addr = models.CharField(max_length=64)
    birthday = models.DateField()

创建表单类来处理 froms.py

from django import forms
from ..models import Author, AuthorDetail

class AuthorForm(forms.ModelForm):
    class Meta:
        model = Author
        fields = ['name', 'age']

class AuthorDetailForm(forms.ModelForm):
    class Meta:
        model = AuthorDetail
        fields = ['gender', 'tel', 'addr', 'birthday']

新增个人信息views.py，注意get_context_data的用法

# Author Views
class AuthorList(LoginRequiredMixin, ListView):
    model = Author
    template_name = 'author_list.html'
    context_object_name = 'authors'

class AuthorCreate(LoginRequiredMixin, CreateView):
    model = Author
    form_class = AuthorForm
    template_name = 'author_form.html'
    success_url = reverse_lazy('author_list')

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        if self.request.method == 'POST':
            context['detail_form'] = AuthorDetailForm(self.request.POST)
        else:
            context['detail_form'] = AuthorDetailForm()
        return context

    def form_valid(self, form):
        context = self.get_context_data()
        detail_form = context['detail_form']
        if detail_form.is_valid():
            author_detail = detail_form.save(commit=False)
            author_detail.save()  # 先保存个人明细页面
            author = form.save(commit=False)
            author.au_detail = author_detail
            author.save() # 再保存个人信息
            return super().form_valid(form)
        else:
            return self.render_to_response(context)

个人列表author_list.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Author List</title>
</head>
<body>
    <h1>Author List</h1>
    <a href="{% url 'author_new' %}">Add New Author</a>
    <ul>
    {% for author in authors %}
        <li>
            {{ author.id }}--
            <a href="{% url 'author_detail' author.id %}">{{ author.name }}</a>--
            <a href="{% url 'author_edit' author.id %}">Edit</a>
            <form action="{% url 'author_delete' author.id %}" method="post" style="display:inline;">
                {% csrf_token %}
                <button type="submit" onclick="return confirm('确定要删除这个作者吗？')">Delete</button>
            </form>
        </li>
    {% endfor %}
    </ul>
</body>
</html>

新增个人信息author_form.html，注意这里和编辑共用的同一个html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{% if object %}Edit{% else %}Add{% endif %} Author</title>
</head>
<body>
    <h1>{% if object %}Edit{% else %}Add{% endif %} Author</h1>
    <form method="post">
        {% csrf_token %}
        {{ form.non_field_errors }}
        {{ form.as_p }}
        {{ detail_form.non_field_errors }}
        {{ detail_form.as_p }}
        <button type="submit">{% if object %}Save changes{% else %}Save{% endif %}</button>
    </form>
    <a href="{% url 'author_list' %}">Back to list</a>
</body>
</html>

veiw加入明细、修改、删除

class AuthorDetail(LoginRequiredMixin, DetailView):
    model = Author
    template_name = 'author_detail.html'
    context_object_name = 'author'

class AuthorUpdate(LoginRequiredMixin, UpdateView):
    model = Author
    form_class = AuthorForm
    template_name = 'author_form.html'
    success_url = reverse_lazy('author_list')

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        if self.request.method == 'POST':
            context['detail_form'] = AuthorDetailForm(self.request.POST, instance=self.object.au_detail)
        else:
            context['detail_form'] = AuthorDetailForm(instance=self.object.au_detail)
        return context

    def form_valid(self, form):
        context = self.get_context_data()
        detail_form = context['detail_form']
        if detail_form.is_valid():
            author_detail = detail_form.save(commit=False)
            author_detail.save()  # Save AuthorDetail first to update it
            author = form.save(commit=False)
            author.au_detail = author_detail
            author.save()
            return super().form_valid(form)
        else:
            return self.render_to_response(context)

class AuthorDelete(LoginRequiredMixin, DeleteView):
    model = Author
    template_name = 'author_confirm_delete.html'
    success_url = reverse_lazy('author_list')

最终的url加入

from django.urls import path

from . import views
from .views import BookAdd, BookList, BookDetail, BookEdit, BookDelete,PublishList,PublishAdd

urlpatterns = [
    path('book/', BookList.as_view(), name='book_list'),
    # path("event_add/", views.event_add, name="event_add"),
    path('book/add/', BookAdd.as_view(), name='book_add'),
    path('book/edit/<int:pk>/', BookEdit.as_view(), name='book_edit'),
    path('book/<int:pk>/', BookDetail.as_view(), name='book_detail'),
    path('book/delete/<int:pk>/', BookDelete.as_view(), name='book_delete'),  # 新增删除路径
    path("publish_add/",PublishAdd.as_view() , name="publish_add"),
    path("publish/", PublishList.as_view(), name="publish_list"),


# Author URLs
    path('authors/', views.AuthorList.as_view(), name='author_list'),
    path('author/<int:pk>/', views.AuthorDetail.as_view(), name='author_detail'),
    path('author/new/', views.AuthorCreate.as_view(), name='author_new'),
    path('author/<int:pk>/edit/', views.AuthorUpdate.as_view(), name='author_edit'),
    path('author/<int:pk>/delete/', views.AuthorDelete.as_view(), name='author_delete'),


]

author_detail.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Author Detail</title>
</head>
<body>
    <h1>{{ author.name }} Details</h1>
    <p>Name: {{ author.name }}</p>
    <p>Age: {{ author.age }}</p>
    <p>Gender: {{ author.au_detail.get_gender_display }}</p>
    <p>Tel: {{ author.au_detail.tel }}</p>
    <p>Address: {{ author.au_detail.addr }}</p>
    <p>Birthday: {{ author.au_detail.birthday }}</p>
    <a href="{% url 'author_list' %}">Back to list</a>
</body>
</html>

多对多

book表再次优化

class Book(models.Model):
    title = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    pub_date = models.DateField()
    # 关联出版社一对多，意思就是一个出版社可以有印刷多本书
    publish = models.ForeignKey("Publish", on_delete=models.CASCADE)
    # 多对多，意思就是多个作者可以编写多本书
    authors = models.ManyToManyField("Author")

生成表结构

1 2	python manage.py makemigrations TestModel# 让 Django 知道我们在我们的模型有一些变更 python manage.py migrate TestModel

注意这里多对多自动生成了一个中间表
然后在from/book.py fields加入authors就可以了

from django import forms

from TestModel.models import Book


class BookForm(forms.ModelForm):
    class Meta:
        model = Book
        fields = ['title', 'price', 'pub_date', 'authors']
    # 你可以在这里添加额外的验证逻辑
    def clean_title(self):
        title = self.cleaned_data['title']
        if not title:
            raise forms.ValidationError("Title is required.")
        return title

在书籍详情页html，加了个循环读取作者信息

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>详情页面</title>
</head>
<body>
<div>
    <p>id:{{ book.id }}</p>
    <p>标题：{{ book.title }}</p>
    <p>价格：{{ book.price }}</p>
    <p>日期：{{ book.pub_date }}</p>
    <p>Authors:
        {% for author in book.authors.all %}
            <a href="{% url 'author_detail' author.id %}">{{ author.name }}</a>{% if not forloop.last %}, {% endif %}
        {% endfor %}
    </p>
</div>
<a href="{% url 'book_list' %}">Back to List</a>

</body>
</html>

本文源代码