第四天作业
1、models
from django.db import models class School(models.Model): name = models.CharField(max_length=20) address = models.CharField(max_length=20) establish_date = models.DateField() class Meta: db_table = 'schools' class Student(models.Model): name = models.CharField(max_length=20) age = models.IntegerField() score = models.FloatField() school = models.ForeignKey(School,on_delete=models.CASCADE) class Meta: db_table = 'students'
2、views
#school_view.py
from django.shortcuts import render
from homeworkapp.models import School
def go_add_school(request):
return render(request,'add_school.html')
def add_school(request):
schname = request.POST["schname"]
schaddress = request.POST["schaddress"]
schdate = request.POST["schdate"]
school = School.objects.create(name=schname,address=schaddress,establish_date=schdate)
return render(request,'add_school.html',{"new_school":school})
#students_view.py
from django.http import HttpResponseRedirect
from django.shortcuts import render, redirect
from django.urls import reverse
from homeworkapp.models import School, Student
def go_add_student(request):
schools = School.objects.all()
return render(request,'add_student.html',locals())
# 添加学生
def add_student(request):
stuname = request.POST["stuname"]
stuage = request.POST["stuage"]
stuscore = request.POST["stuscore"]
school_id = request.POST["school"]
School.objects.create(name=stuname,age=stuage,score=stuscore,school_id=school_id)
return HttpResponseRedirect('/homework/allstudents/') # 重定向
# 显示所有学生信息
def show_all_students(request):
students = Student.objects.all()
return render(request, 'all_students.html', {"students": students})
def detail_student(request,stuid):
student = Student.objects.get(id=stuid)
return render(request,'student_detail.html',locals())
3、templates
<!add_school.html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>添加学校</title>
</head>
<body>
{% if new_school %}
<h3> <span style="color:red">{{ new_school.name }}</span>添加成功！</h3>
{% endif %}
<form action="/homework/addschool/" method="post">
{% csrf_token %}
学校名称：<input type="text" name="schname"><br/>
学校地址：<input type="text" name="schaddress"><br/>
建校日期：<input type="date" name="schdate"/> <br/>
<input type="submit" value="创建学校"/>
</form>
<br/>
<a href="/homework/gostudent/">添加学生</a>
</body>
</html>
<!all_studdents.html>
<!add_student.html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>添加学生页面</title>
</head>
<body>
<form action="/homework/addstudent/" method="post">
{% csrf_token %}
新生姓名：<input type="text" name="stuname"/> <br/>
新生年龄：<input type="text" name="stuage"/> <br/>
新生成绩：<input type="text" name="stuscore"/> <br/>
所属学校：<select name="school">
{% for school in schools %}
<option value="{{ school.id }}">{{ school.name }}</option>
{% endfor %}
</select> <br/>
<input type="submit" value="添加学生"/>
</form>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>所有学生信息</title>
</head>
<body>
<table border="1" align="center">
<thead>
<tr>
<th>学号</th>
<th>姓名</th>
<th>年龄</th>
<th>成绩</th>
<th>学校</th>
</tr>
</thead>
<tbody>
{% for student in students %}
<tr>
<td>{{ student.id }}</td>
<td> <a href="{% url 'home:detail' student.id %}"> {{ student.name }} </a></td>
<td>{{ student.age }}</td>
<td>{{ student.score }}</td>
<td>{{ student.school.name }}</td>
</tr>
{% endfor %}
</tbody>
</table>
</body>
</html>
<!student_detail.html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>{{ student.name }}</title>
</head>
<body>
<form action="" method="post">
学号：<input type="text" value="{{ student.id }}" readonly/> <br/>
姓名：<input type="text" value="{{ student.name }}"/> <br/>
年龄：<input type="text" value="{{ student.age }}"/> <br/>
成绩：<input type="text" value="{{ student.score }}"/> <br/>
学校：<input type="text" value="{{ student.school.name }}"/> <br/>
<input type="submit" value="修改"/>
</form>
</body>
</html>
4、urls
#homeworke/urls.py 子路由
from django.urls import path
from homeworkapp.views.school_views import *
from homeworkapp.views.student_view import *
app_name = "homeworkapp"
urlpatterns = [
path('goschool/',go_add_school),
path('addschool/',add_school),
path('gostudent/',go_add_student),
path('addstudent/',add_student),
path('student/<stuid>/',detail_student,name="detail"),
path('allstudents/',show_all_students),
#urls.py 总路由
from django.contrib import admin
from django.urls import path,include
urlpatterns = [
path('admin/', admin.site.urls),
path('homework/',include('homeworkapp.urls',namespace="home")),
path('reverse/',include('reverseapp.urls',namespace="rev")),
]
一：模型外键自关联(引用)
当一个表中的记录存在层级关系时，使用外键自引用。 模型中创建外键自引用，使用'self'或'本模型类名称' models.ForeignKey('self',on_delete=models.CASCADE,null=True) 或 models.ForeignKey('本模型类名称',on_delete=models.CASCADE,null=True)
1、创建"老板"(没有对应的上级记录)
将外键自关联字段设置为Noneemp1 = Emp.objects.create(name="马云",parent_emp=None)
2、创建下层记录，将外键关联引用字段与上级记录关联
方式一：使用实例化对象关联emp2 = Emp.objects.create(name='张三',parent_emp=emp1)
方式二：使用外键值关联emp3 = Emp.objects.create(name='李四',parent_emp_id=2)
3、获取上级记录
例如：查询6号员工的直属领导 emp = Emp.objects.get(id=6) # 查询6号员工 manager = Emp.objects.get(id=emp.parent_emp_id) # 查询直属领导
4、删除上级记录后，所关联的下级记录也会级联删除
emp = Emp.objects.get(id=2)emp.delete()
1、models
from django.db import models
class Emp(models.Model):
name = models.CharField(max_length=20)
age = models.IntegerField()
sex = models.CharField(max_length=10)
hire_date = models.DateField()
salary = models.FloatField()
parent_emp = models.ForeignKey('self',on_delete=models.CASCADE,null=True) #外键使用self关联自己
class Meta:
db_table = 'emp'
class Official(models.Model):
name = models.CharField(max_length=20)
sex = models.CharField(max_length=10)
parent_official = models.ForeignKey('Official',on_delete=models.CASCADE,null=True)#使用自生类名关联
class Meta:
db_table = 'officials'
2、Terminal
rosoft Windows [版本 10.0.17763.55]
(c) 2018 Microsoft Corporation。保留所有权利。
C:\python\DjangoDay5> python manage.py makemigrations
Migrations for 'selfapp':
selfapp\migrations\0001_initial.py
- Create model Emp
- Create model Official
C:\python\DjangoDay5>python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, selfapp, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying selfapp.0001_initial... OK
Applying sessions.0001_initial... OK
C:\python\DjangoDay5>python manage.py shell
Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 27 2018, 04:59:51) [MSC v.1914 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from selfapp.models import *
>>> emp1 = Emp.objects.create(name="马云",age=55,sex="man",hire_date='1995-09-05',salary=10000,parent_emp=None)
>>> emp2 = Emp.objects.create(name="马利",age=45,sex="woman",hire_date='199
8-09-05',salary=8000,parent_emp=emp1)
>>> emp3 = Emp.objects.create(name="李四",age=48,sex="man",hire_date='1998-
11-05',salary=9000,parent_emp=emp1)
>>> emp4 = Emp.objects.create(name="张三",age=38,sex="man",hire_date='2008-
11-05',salary=5000,parent_emp_id=3)
>>> emp5 = Emp.objects.create(name="小红",age=28,sex="man",hire_date='2008-
11-05',salary=5000,parent_emp_id=4)
#查询下级成员
>>> emp = Emp.objects.get(id=1)
>>> emp.name
'马云'
>>> emps = Emp.objects.filter(parent_emp=emp)
>>> for e in emps:
... print(e.name)
...
马利
李四
>>> emps = Emp.objects.filter(parent_emp_id=1)
>>> for e in emps:
... print(e.name)
... )
马利
李四
#查询上级
>>> emp2 = Emp.objects.get(id=5)
>>> emp2.name
'小红'
>>> manager = Emp.objects.get(id=emp2.parent_emp_id)
>>> manager.name
'张三'
>>> manager = Emp.objects.filter(id=emp2.parent_emp_id)
>>> manager = Emp.objects.get(id=emp2.parent_emp_id)
>>> manager.name
'张三'
>>> emp = Emp.objects.get(id=1)
>>> emp.delete() #级联删除
(5, {'selfapp.Emp': 5})
Official模型
>>> o1 =Official(name='zs',sex='boy',parent_official=None) #创建顶级对象
>>> o1.save()
>>> o2 =Official.objects.create(name='ls',sex='boy',parent_official=o1) #创建一级对象，父级为o1
>>> o3 =Official.objects.create(name='ww',sex='boy',parent_official=o2) #创建二级对象，父级为o2
>>> o1 = Official.objects.get(id=1) #获取对象
>>> o1.delete() #删除，会级联删除
(3, {'selfapp.Official': 3})
>>>
3、mysql
ywh@ubuntu:~$ mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.24-0ubuntu0.16.04.1 (Ubuntu) Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> drop database mydb; Query OK, 11 rows affected (0.09 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.00 sec) mysql> create database mydb default character set utf8; Query OK, 1 row affected (0.00 sec) mysql> use mydb Database changed mysql> show tables; Empty set (0.00 sec) mysql> show tables; +----------------------------+ | Tables_in_mydb | +----------------------------+ | auth_group | | auth_group_permissions | | auth_permission | | auth_user | | auth_user_groups | | auth_user_user_permissions | | django_admin_log | | django_content_type | | django_migrations | | django_session | | emp | | officials | +----------------------------+ 12 rows in set (0.00 sec) mysql> select * from emp; +----+--------+-----+-----+------------+--------+---------------+ | id | name | age | sex | hire_date | salary | parent_emp_id | +----+--------+-----+-----+------------+--------+---------------+ | 1 | 马云 | 55 | man | 1995-09-05 | 10000 | NULL | +----+--------+-----+-----+------------+--------+---------------+ 1 row in set (0.00 sec) mysql> select * from emp; +----+--------+-----+-------+------------+--------+---------------+ | id | name | age | sex | hire_date | salary | parent_emp_id | +----+--------+-----+-------+------------+--------+---------------+ | 1 | 马云 | 55 | man | 1995-09-05 | 10000 | NULL | | 2 | 马利 | 45 | woman | 1998-09-05 | 8000 | 1 | | 3 | 李四 | 48 | man | 1998-11-05 | 9000 | 1 | | 4 | 张三 | 38 | man | 2008-11-05 | 5000 | 3 | +----+--------+-----+-------+------------+--------+---------------+ 4 rows in set (0.00 sec) mysql> select * from emp; +----+--------+-----+-------+------------+--------+---------------+ | id | name | age | sex | hire_date | salary | parent_emp_id | +----+--------+-----+-------+------------+--------+---------------+ | 1 | 马云 | 55 | man | 1995-09-05 | 10000 | NULL | | 2 | 马利 | 45 | woman | 1998-09-05 | 8000 | 1 | | 3 | 李四 | 48 | man | 1998-11-05 | 9000 | 1 | | 4 | 张三 | 38 | man | 2008-11-05 | 5000 | 3 | | 5 | 小红 | 28 | man | 2008-11-05 | 5000 | 4 | +----+--------+-----+-------+------------+--------+---------------+ 5 rows in set (0.00 sec) mysql> select * from emp; #删除后查询 Empty set (0.00 sec) mysql> select * from officials; +----+------+-----+--------------------+ | id | name | sex | parent_official_id | +----+------+-----+--------------------+ | 1 | zs | boy | NULL | +----+------+-----+--------------------+ 1 row in set (0.02 sec) mysql> select * from officials; +----+------+-----+--------------------+ | id | name | sex | parent_official_id | +----+------+-----+--------------------+ | 1 | zs | boy | NULL | | 2 | ls | boy | 1 | | 3 | ww | boy | 2 | +----+------+-----+--------------------+ 3 rows in set (0.00 sec) mysql> select * from officials; #删除后查询为空 Empty set (0.00 sec)
二：URL反向解析
通过反向解析URL，可以在不改变模板链接路径的情况下，路由可以变化。 URL反向解析的实现： 第一步：设置命名空间 include('子路由模块路径',namespace="在此设置命名空间")
第二步：在path()函数的第三个name关键字参数中指定名称 path('路由地址/',视图函数名,name="在此设置name"),
第三步：在子路由(应用中的urls.py)中设置app_name app_name = "最好设置为应用名"
如何在模板中使用反向解析？{% url 'namespace名称:name名称' 参数1 参数2 ... %}
三：服务端跳转（转发）和客户端跳转（重定向）
服务端跳转（转发）：将客户端发送的请求在后台服务器进行传递转发。 请求参数可以在后台传递，浏览器的URL地址不变。 实现服务端跳转：返回HttpResponse；返回render()。
客户端跳转（重定向）：客户端向服务端发送两次不同的请求。 浏览器的URL地址改变。 实现客户端跳转： 方式一： HttpResponseRedirect('重定向的URL') 方式二： redirect()与reverse()结合使用，请思考？
四：CSRF
CSRF：跨网站请求伪造 如果开启了CsrfViewMiddleware中间件，则每次post请求都会检查令牌(token)是否 正确。 在表单中使用{% csrf_token %}标签，可以动态生成token令牌。