Django增删改查--图书管理系统

其他 2019-04-01 20:14:44 阅读次数: 0

一对一     出版社信息的增删改查

 一对多    出版社信息与书籍信息的增删改查

 多对多    书籍信息与作者信息的增删改查

建表

from django.db import models

class Publisher(models.Model):
    pid = models.AutoField(primary_key=True)            # 自增字段且设置为主键
    name = models.CharField(max_length=32,unique=True)  # 设置唯一

    def __str__(self):
        return "{}--{}".format(self.pid,self.name)


class Book(models.Model):
    name = models.CharField(max_length=32,unique=True)
    pub = models.ForeignKey('Publisher',on_delete=models.CASCADE)    # 外键  要链接的类名可以直接写,也可以写在字符串内    级联删除

class Author(models.Model):
    name = models.CharField(max_length=32)
    books = models.ManyToManyField('Book')     # 多对多,生成第三张表
orm建表

 一对一

 1.设计URL

URL

 2.写函数

from app01 import models

def publisher_list(request):
    '''展示数据'''
    # 获取数据库内所有出版社的数据
    publishers = models.Publisher.objects.all().order_by('pid')      # 获取对象列表并按照pid字段排序
    return render(request,'publisher_list.html',{'publishers':publishers})  # 第三个参数是为了给html文件传值调用

def add_publisher(request):
    '''新增数据'''
    if request.method == 'POST':
        # 获取提交的数据(括号内为input的name属性值),没有默认空字符串
        new_name = request.POST.get('new_name','').strip()
        # 设定输入不能为空
        if not new_name:
            return render(request,'add_publisher.html',{'err_msg':'输入不能为空','name':new_name})
        # 设定不能与数据库现有数据重复
        obj_list =  models.Publisher.objects.filter(name=new_name)    # 在数据库中查询数据是否存在
        if obj_list:        # 数据重复
            return render(request, 'add_publisher.html', {'err_msg': '出版社名称已存在', 'name': new_name})
        # orm往数据库中写入数据
        if new_name and not obj_list:
            models.Publisher.objects.create(name=new_name)
            return redirect('/publisher_list/')
    # 如果不是post请求,还是返回本页面
    return render(request,'add_publisher.html')

def delete_publisher(request):
    '''删除数据'''
    # 找到需要删除的数据的id
    pk = request.GET.get('pk')
    # 通过id在数据库中找到对应的数据
    obj = models.Publisher.objects.filter(pid=pk)
    # 如果数据不存在(通过地址栏指定id进行删除)
    if not obj:
        return HttpResponse('要编辑的数据不存在')
    # 删除数据 返回展示页面
    obj.delete()
    return redirect('/publisher_list/')

def edit_publisher(request):
    # 找到需要编辑的数据的id
    pk = request.GET.get('pk')
    # 通过id在数据库中找到对应的数据  对象列表<QuerySet [<Publisher: 1--人民邮电出版社>]>
    obj_list = models.Publisher.objects.filter(pk=pk)
    # 如果数据不存在(通过地址栏指定id进行编辑)
    if not obj_list:
        return HttpResponse('要编辑的数据不存在')
    # 拿到数据    1--人民邮电出版社
    obj = obj_list[0]
    err_msg = ''
    if request.method == 'POST':
        # 获取用户输入的数据
        new_name = request.POST.get('new_name','').strip()
        # 设定输入不能为空,返回添加页面
        if not new_name:
            err_msg = '输入不能为空'
            # return render(request, 'edit_publisher.html', {'obj': obj, 'err_msg': '输入不能为空'})
        # 设定不能与数据库现有数据重复
        obj_list = models.Publisher.objects.filter(name=new_name)  # 在数据库中查询数据是否存在
        if obj_list:                      #有重复数据,返回添加页面
            err_msg = '出版社名称已存在'
            # return render(request, 'edit_publisher.html', {'obj': obj, 'err_msg': '出版社名称已存在'})
        #修改数据
        if new_name and not obj_list:
            obj.name = new_name    # 在内存中修改
            obj.save()             # 写入数据库
            return redirect('/publisher_list/')   #跳转到展示页面

        return render(request,'edit_publisher.html',{'obj':obj,'err_msg':err_msg})
    return render(request, 'edit_publisher.html')
函数

 3.写模板

在模板中    {% 逻辑 %} 表示逻辑        {{ 变量 }},可以使用函数传的参数进行渲染

<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>出版社信息</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<div class="container">
    <a class="btn btn-success" href="/add_publisher/" role="button">新增</a>
    <table class="table table-condensed">
        <thead>
        <tr>
            <th>序号</th>
            <th>ID</th>
            <th>名称</th>
            <th>操作</th>
        </tr>
        </thead>
        <tbody>
        {% for foo in publishers %}           # 开始循环
            <tr>
                <td>{{ forloop.counter }}</td>
                <td>{{ foo.pk }}</td>
                <td>{{ foo.name }}</td>
                <td>
                    <a class="btn btn-info" href="/delete_publisher/?pk={{ foo.pk }}" role="button">删除</a>
                    <a class="btn btn-info" href="/edit_publisher/?pk={{ foo.pk }}" role="button">编辑</a>
                </td>
            </tr>
        {% endfor %}                        # 结束循环
        </tbody>
    </table>
</div>
</body>
</html>
publisher_list 
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加信息</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<div class="container">
    <form class="form-horizontal" method="post" action="">
    <div class="form-group">
            <label for="inputName3" class="col-sm-2 control-label">名称</label>
        <div class="col-sm-5">
            <input type="text" class="form-control" name="new_name" placeholder="出版社名称" value="{{ name }}">
            <span>{{ err_msg }}</span>
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="submit" class="btn btn-default">提交</button>
        </div>
    </div>
</form>
</div>

</body>
</html>
add_publisher 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>编辑信息</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<div class="container">
    <form class="form-horizontal" method="post" action="">
    <div class="form-group">
            <label for="inputName3" class="col-sm-2 control-label">名称</label>
        <div class="col-sm-5">
            <input type="text" class="form-control" name="new_name" value="{{ obj.name}}">
            <span>{{ err_msg }}</span>
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="submit" class="btn btn-default">提交</button>
        </div>
    </div>
</form>
</div>
</body>
</html>
edit_publisher

一对多

1.设计URL

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'^delete_publisher/', views.delete_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),
    url(r'^edit_book/', views.edit_book),
]
URL对应

2.写函数

def book_list(request):
    '''书籍数据展示'''
    # 将数据库中的数据读取出来
    books = models.Book.objects.all()      #对象列表
    return render(request,'book_list.html',{'books':books})

def add_book(request):
    '''添加书籍信息'''
    # 获取所有出版社信息
    publishers = models.Publisher.objects.all()
    if request.method == 'POST':
        # 获取提交的数据
        new_name = request.POST.get('new_name','').strip()
        pub_id = request.POST.get('pub_id')
        err_msg = ''
        # 不能为空
        if not new_name:
            err_msg = '输入不能为空'
        # 不能与现有书籍重复
        obj = models.Book.objects.filter(name=new_name)
        if obj:
            err_msg = '书籍已存在'
        # 写入数据库
        if new_name and not obj:
            models.Book.objects.create(name=new_name,pub_id=pub_id)
            # 跳转到展示页面
            return redirect('/book_list/')
        return render(request,'add_book.html',{'publishers':publishers,'err_msg':err_msg,'new_name':new_name})
    # 如果不是post请求
    return render(request,'add_book.html',{'publishers':publishers})

def del_book(request):
    '''删除书籍'''
    # 获取删除数据的pk
    pk = request.GET.get('pk')
    # 根据pk在数据库中找出对应的数据
    obj = models.Book.objects.filter(pk=pk)
    # 如果pk不存在
    if not obj:
        return HttpResponse('要删除的数据不存在')
    # 删除数据
    obj.delete()
    # 返回展示页面
    return redirect('/book_list/')

def edit_book(request):
    '''编辑书籍信息'''
    # 找到需要编辑数据的pk
    pk = request.GET.get('pk')
    #根据pk找到数据库中的对应的数据
    obj_list = models.Book.objects.filter(pk=pk)
    obj = obj_list[0]
    publishers = models.Publisher.objects.all()
    if request.method == 'POST':
        # 获取提交的数据
        new_name = request.POST.get('new_name','').strip()
        pub_id = request.POST.get('pub_id','').strip()
        err_msg = ''
        if not new_name:
            err_msg = '输入不能为空'
        book_obj = models.Book.objects.filter(name=new_name)
        if book_obj:
            err_msg = '书籍已存在'
        if new_name and not book_obj:
            obj.name = new_name
            obj.pub_id = pub_id
            obj.save()
            return redirect('/book_list/')
        return render(request,'edit_book.html',{'err_msg':err_msg,'obj':obj,'publishers':publishers})
    return render(request,'edit_book.html',{'publishers':publishers,'obj':obj})
函数

3.写模板

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>书籍信息</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<div class="container">
    <div class="panel panel-primary" style="margin-top: 50px">
        <div class="panel-heading">书籍信息</div>
        <div class="panel-body">
            <a class="btn btn-primary" href="/add_book/" role="button">新增</a>
            <table class="table table-condensed">
                <thead>
                <tr>
                    <th>序号</th>
                    <th>ID</th>
                    <th>书名</th>
                    <th>出版社</th>
                    <th>操作</th>
                </tr>
                </thead>
                <tbody>
                {% for book in books %}
                    <tr>
                        <td>{{ forloop.counter }}</td>
                        <td>{{ book.pk }}</td>
                        <td>{{ book.name }}</td>
                        <td>{{ book.pub.name }}</td>
                        <td>
                            <a class="btn btn-danger" href="/del_book/?pk={{ book.pk }}" role="button">删除</a>
                            <a class="btn btn-success" href="/edit_book/?pk={{ book.pk }}" role="button">编辑</a>
                        </td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>

</div>

</body>
</html>
book_list 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加书籍信息</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<div class="container">
    <div class="panel panel-primary" style="margin-top: 50px">
        <div class="panel-heading">添加书籍信息</div>
        <div class="panel-body">
            <form class="form-horizontal" method="post" action="">
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">书名</label>
                    <div class="col-sm-5">
                        <input type="text" class="form-control" name="new_name" placeholder="书名" value="{{ new_name }}">
                        <span>{{ err_msg }}</span>
                    </div>
                </div>
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">出版社</label>
                    <div class="col-sm-5">
                        <select name="pub_id" id="" class="form-control">
                            {% for publisher in publishers %}
                                <option value="{{ publisher.pk }}">{{ publisher.name }}</option>
                                <span>{{ err_msg }}</span>
                            {% endfor %}
                        </select>
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-sm-offset-2 col-sm-10">
                        <button type="submit" class="btn btn-default">提交</button>
                    </div>
                </div>
            </form>
        </div>
    </div>

</div>

</body>
</html>
add_book 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>编辑书籍信息</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
          integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>
<div class="container">
    <div class="panel panel-primary" style="margin-top: 50px">
        <div class="panel-heading">编辑书籍信息</div>
        <div class="panel-body">
            <form class="form-horizontal" method="post" action="">
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">书名</label>
                    <div class="col-sm-5">
                        <input type="text" class="form-control" name="new_name" value="{{ obj.name }}">
                        <span>{{ err_msg }}</span>
                    </div>
                </div>
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">出版社</label>
                    <div class="col-sm-5">
                        <select name="pub_id" id="" class="form-control">
                            {% for publisher in publishers %}
                                {% if publisher == obj.pub %}
                                    <option selected value="{{ publisher.pk }}">{{ publisher.name }}</option>
                                {% else %}
                                    <option value="{{ publisher.pk }}">{{ publisher.name }}</option>
                                {% endif %}
                            {% endfor %}
                        </select>
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-sm-offset-2 col-sm-10">
                        <button type="submit" class="btn btn-default">提交</button>
                    </div>
                </div>
            </form>
        </div>
    </div>

</div>
</body>
</html>
edit_book

多对多

1.设计URL

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^publisher_list/', views.publisher_list),
    url(r'^add_publisher/', views.add_publisher),
    url(r'^delete_publisher/', views.delete_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),
    url(r'^edit_book/', views.edit_book),

    url(r'^author_list/', views.author_list),
    url(r'^add_author/', views.add_author),
    url(r'^del_author/', views.del_author),
    url(r'^edit_author/', views.edit_author),
]
URL对应

2.写函数

def author_list(request):
    '''展示作者'''
    authors = models.Author.objects.all()
    # for i in authors:
    #     print(i.books)           # 关系管理对象
    #     print(i.books.all())     # 关联的书籍对象
    return render(request,'author_list.html',{'authors':authors})

def add_author(request):
    '''新增作者'''
    if request.method == 'POST':
        name = request.POST.get('name')
        book_id = request.POST.getlist('book_id')   # get方法只会取一条数据,书籍为多选,使用getlist方法,结果为列表
        # 写入数据库,返回展示页面
        author_obj = models.Author.objects.create(name=name)   # 创建作者对象
        author_obj.books.set(book_id)    # set方法 设置作者和书籍的多对多的关系  每次都是重新设置.删除原有数据,生成新的id
        return redirect('/author_list/')
    books = models.Book.objects.all()
    return render(request,'add_author.html',{'books':books})

def del_author(request):
    '''删除作者'''
    pk = request.GET.get('pk')
    models.Author.objects.filter(pk=pk).delete()
    return redirect('/author_list/')

def edit_author(request):
    '''编辑作者'''
    pk = request.GET.get('pk')
    edit_obj = models.Author.objects.get(pk=pk)
    if request.method == 'POST':
        name = request.POST.get('name')
        books_id = request.POST.getlist('book_id')
        edit_obj.name = name
        edit_obj.save()
        edit_obj.books.set(books_id)  # 修改作者与书籍的多对多关系
        return redirect('/author_list/')
    books = models.Book.objects.all()
    return render(request,'edit_author.html',{'obj':edit_obj,'books':books})
函数

3.写模板

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>作者信息</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7/css/bootstrap.css">
</head>
<body>
<div class="container">
    <div class="panel panel-primary" style="margin-top: 50px">
        <div class="panel-heading"><h4>作者信息</h4></div>
        <div class="panel-body">
            <a class="btn btn-primary" href="/add_author/" role="button">新增</a>
            <table class="table table-condensed">
                <thead>
                <tr>
                    <th>序号</th>
                    <th>ID</th>
                    <th>作者</th>
                    <th>代表作</th>
                    <th>操作</th>
                </tr>
                </thead>
                <tbody>
                {% for author in authors %}
                    <tr>
                        <td>{{ forloop.counter }}</td>
                        <td>{{ author.pk }}</td>
                        <td>{{ author.name }}</td>
                        <td>
                            {% for book in author.books.all %}
                                {{ book.name }}
                            {% endfor %}
                        </td>
                        <td>
                            <a class="btn btn-danger" href="/del_author/?pk={{ author.pk }}" role="button">删除</a>
                            <a class="btn btn-success" href="/edit_author/?pk={{ author.pk }}" role="button">编辑</
                        </td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
        </div>
    </div>

</div>

</body>

</html>
author_list 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加作者信息</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7/css/bootstrap.css">
</head>
<body>
<div class="container">
    <div class="panel panel-primary" style="margin-top: 50px">
        <div class="panel-heading">添加作者信息</div>
        <div class="panel-body">
            <form class="form-horizontal" method="post" action="">
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">姓名</label>
                    <div class="col-sm-5">
                        <input type="text" class="form-control" name="name" placeholder="姓名">
                        <span>{{ err_msg }}</span>
                    </div>
                </div>
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">代表作</label>
                    <div class="col-sm-5">
                        <select name="book_id" id="" class="form-control" multiple>
                            {% for book in books %}
                                <option value="{{ book.pk }}">{{ book.name }}</option>
                            {% endfor %}
                        </select>
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-sm-offset-2 col-sm-10">
                        <button type="submit" class="btn btn-default">提交</button>
                    </div>
                </div>
            </form>
        </div>
    </div>
</div>
</body>
</html>
add_author 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>修改作者信息</title>
    <link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7/css/bootstrap.css">
</head>
<body>
<div class="container">
    <div class="panel panel-primary" style="margin-top: 50px">
        <div class="panel-heading">编辑作者信息</div>
        <div class="panel-body">
            <form class="form-horizontal" method="post" action="">
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">姓名</label>
                    <div class="col-sm-5">
                        <input type="text" class="form-control" name="new_name" value="{{ obj.name }}">
                    </div>
                </div>
                <div class="form-group">
                    <label for="inputName3" class="col-sm-2 control-label">代表作</label>
                    <div class="col-sm-5">
                        <select name="book_id" id="" class="form-control" multiple>
                            {% for book in books %}
                                {% if book in obj.books.all %}
                                    <option selected value="{{ book.pk }}">{{ book.name }}</option>
                                {% else %}
                                    <option value="{{ book.pk }}">{{ book.name }}</option>
                                {% endif %}
                            {% endfor %}
                        </select>
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-sm-offset-2 col-sm-10">
                        <button type="submit" class="btn btn-default">提交</button>
                    </div>
                </div>
            </form>
        </div>
    </div>

</div>
</body>
</html>
edit_author

创建多对多关系的三种方式

1.Django创建第三张表

class Author(models.Model):
   name = models.CharField(max_length=32)
   books = models.ManyToManyField('Book')  # 表示多对多的关系  生成第三张表

2.自己创建第三张表

　　可以在第三张表中添加另外的字段和数据,利用django直接创建是做不到的,但是查询数据比较复杂

class Author(models.Model):
   name = models.CharField(max_length=32)


class Author_Book(models.Model):
   author = models.ForeignKey('Author')
   book = models.ForeignKey('Book')
   time = models.CharField(max_length=32)

3.Django + 自建表

　　通过Django和自建表的形式,既可以在表中添加字段和数据,也解决了查询困难的事情

class Author(models.Model):
    name = models.CharField(max_length=32)
    books = models.ManyToManyField('Book',through='Author_Book')  # 表示多对多的关系 

class Author_Book(models.Model):
   author = models.ForeignKey('Author')
   book = models.ForeignKey('Book')
   time = models.CharField(max_length=32)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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