多表查询 多对多关系之老师表单的增删改查

表单的建立

from django.db import models

# Create your models here.
#创建教室表单
class Class_list(models.Model):
    id=models.AutoField(primary_key=True)
    cname=models.CharField(max_length=32)
    first_day=models.DateField()
    def __str__(self):
        return self.cname

#创建老师表单
class Teacher(models.Model):
    tname=models.CharField(max_length=32)

    cid=models.ManyToManyField("Class_list")
    #设置manytomant 外键，他自动生成了第三个关联老师和教室的对应关系表

 

 

第三张表上放的每一个值实际上 可以指带的是一个对象（一条数据） 而不单单是一个id#  也可以是id}

 

查看老师信息

html页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>teacher_list</title>
</head>
<body>
{% csrf_token %}

<div class="c1">
    <button type="button"><span><a href='{% url 'add_teacher' %}' >新增</a></span></button>
</div>
<div class="c2">
    <table border="2">
        <thead>
        <tr>
            <th>序号</th>
            <th>id</th>
            <th>姓名</th>
            <th>班级</th>
            <th>功能</th>
        </tr>
        </thead>
        <tbody>
        {% for teacher in teacher_list %}
            <tr>

                <td> {{ forloop.counter }}</td>
                <td>{{ teacher.id }}</td>
                <td>{{ teacher.tname }}</td>
                  <td>
                    {% for class in teacher.cid.all %}
                        {{ class.cname }}
                    {% endfor %}
                  </td>


                <td>
                    <a href="">aaa</a>
{#                    <button type="button"><span><a href="{% url 'delete_class' class.id %}">删除</a></span></button>#}
                    <button type="button"><span><a href="{% url 'edit_teacher' teacher.id  %} ">编辑</a></span></button>
                </td>

            </tr>
        {% endfor %}
        </tbody>
    </table>
</div>

</body>
</html>
View Code

 编辑老师信息

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Title</title>
</head>
<body>
<form action="{% url 'edit_teacher' teacher.id  %}" method="post">
    {% csrf_token %}
    <input type="text" name="id" style="display:none" value="{{ teacher.id }}">
    <span>名字</span>
    <input type="text" name="tname" value="{{ teacher.tname }}">
    <span>班级</span>
    <select name="class_id" id="" multiple>

        {% for class in class_list  %}
{#            注意这里写法，因为第三张表上放的每一个值实际上指的是一个对象（一条数据）  而不单单是一个id#}
{#          所以这里这样写，   #}
            {% if class in teacher.cid.all %}
            <option selected value="{{ class.id }}" >{{ class.cname }}</option>
            {% else %}
            <option value="{{ class.id }}" >{{ class.cname }}</option>
            {% endif %}

        {% endfor %}
    </select>
    <button type="submit">提交</button>
</form>

</body>
</html>

viwe中的写法

查询

def teacher_list(request):
    ret=models.Teacher.objects.all()
    print(ret)
    return render(request,'teacher_list.html',{'teacher_list':ret})

编辑

#多对多之编辑
def  edit_teacher(request,args):

    tid=args
    ret=models.Teacher.objects.get(id=tid)
    class_list=models.Class_list.objects.all()

    return render(request,'edit_teacher.html',{'teacher':ret,'class_list':class_list})

 

posted on 2018-01-24 20:40  王大拿  阅读(252)  评论(0)    收藏  举报

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