django day3

from django.shortcuts import HttpResponse, render, redirect
from app01 import models
# Create your views here.

# 展示出版社列表
def publisher_list(request):
    # 去数据库查出所有的出版社,填充到HTML中,给用户返回
    ret = models.Publisher.objects.all().order_by("id")
    return render(request, "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
    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
            models.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("/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, "add_publisher.html", {"error": error_msg})


# 删除出版社的函数
def delete_publisher(request):
  
    # 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("/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.GET.get("nid")
        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("/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, "edit_publisher.html", {"publisher": publisher_obj})
    else:
        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, "book_list.html", {"all_book": all_book})

# 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("/book_list/")


# 添加书籍
def add_book(request):
    if request.method == "POST":
        # print(request.POST)
        # print("=" * 120)
        # {"book_title": "跟金老板学开车", "publisher": 9}
        new_title = request.POST.get("book_title")
        new_publisher_id = request.POST.get("publisher")
        print(new_publisher_id)
        # 创建新书对象,自动提交
        models.Book.objects.create(title=new_title, publisher_id=new_publisher_id)

        # 用出版社对象创建
        # publisher_obj = models.Publisher.objects.get(id=new_publisher_id)
        # models.Book.objects.create(title=new_title, publisher=publisher_obj)

        # 返回到书籍列表页
        return redirect("/book_list/")

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


# 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.GET.get("nid")
        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("/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)
    print(edit_book_obj.id)
    print(edit_book_obj.title)
    print(edit_book_obj.publisher)  # 取到当前书籍对象关联的出版社对象
    print(edit_book_obj.publisher_id)  # 取到当前书籍对象关联的出版社的id值

    ret = models.Publisher.objects.all()
    return render(request, "edit_book.html",{"publisher_list": ret, "book_obj": edit_book_obj} )

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, unique=True,verbose_name=u'出版社名')
    addr = models.CharField(max_length=128)


# 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,verbose_name=u'书名')
    # 和出版社关联的外键字段
    publisher = models.ForeignKey(to="Publisher")

编辑书：

<form action="/edit_book/?nid={{ book_obj.id }}" method="post">
    <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>

<h1>添加书籍</h1>
<form action="/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>

book_list:
<tbody>
{% for i in all_book %}
    <tr>
    <td>{{ forloop.counter }}</td>
    <td>{{ i.id }}</td>
    <td>{{ i.title }}</td>
    <td>{{ i.publisher.name }}</td>
    <td>
        <a href="/delete_book/?id={{ i.id }}">删除</a>
        <a href="/edit_book/?id={{ i.id }}">编辑</a>
    </td>
    </tr>
{% endfor %}
</tbody>