Django入门
Django文档:
https://docs.djangoproject.com/en/1.10/ref/
一、简单创建app
1.1 命令行创建project和app。
django-admin startproject HelloWorld
cd HelloWorld
python manage.py startapp app01
1.2 pycharm创建app
2、将app01加入settings并配置url。
3、启动app
python manage.py runserver 8000
二、
生成环境:
settings.py
DEBUG = False
ALLOWED_HOSTS = ["*"]
2.1 配置加载html
或者通过render()返回html页面。
1
2
3
4
|
def login(request): # content = open("templates/app01/login.html","r").read() # return HttpResponse(content) return render(request, "app01/login.html" ) |
注意html里的加载的css,jq,js用http的方式或配置静态文件的方式引入。
2.2 django将表应用到数据库。
python manage.py makemigration #根据class创建创建数据库的配置文件
python manage.py migrate # 根据配置文件创建数据库表
2.3 django创建后台管理员账户
python manage.py createsuperuser
2.4 路由系统
动态路由,正则表达式: 这个(\d+) 会传入news(request,nid)函数。
二级路由
首先创建app01, python manage.py startapp app02
from django.conf.urls import url,include
,在app01目录下的urls.py下配置urls
,在app02目录下的urls.py下配置urls
2.5 数据库操作
数据库连接:
1
2
3
4
5
6
7
8
9
10
|
DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': 'day15', 'HOST':'127.0.0.1', 'PORT':'3306', 'USER':'root', 'PASSWORD':'root', } } |
modles.py
1
2
3
4
5
|
class UserInfo(models.Model): username = models.CharField(max_length = 32 ) password = models.CharField(max_length = 32 ) age = models.IntegerField() # 默认会自动添加自增的id作为主键 |
一对多,多对多
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
class Author(models.Model): first_name = models.CharField(max_length = 32 ) last_name = models.CharField(max_length = 32 ) email = models.EmailField() class Publisher(models.Model): name = models.CharField(max_length = 64 ,unique = True ) address = models.CharField(max_length = 128 ) city = models.CharField(max_length = 64 ) state_province = models.CharField(max_length = 30 ) country = models.CharField(max_length = 50 ) website = models.URLField() class Book(models.Model): bookname = models.CharField(max_length = 128 ) authors = models.ManyToManyField(Author) publisher = models.ForeignKey(Publisher) publish_date = models.DateField() |
然后,执行python manage.py makemigrations ; python manage.py migrate
1
2
3
4
5
6
7
8
9
10
11
12
13
|
E:\day15>python2 manage.py makemigrations Migrations for 'app01' : app01\migrations\ 0002_auto_20160807_2043 .py: - Create model Author - Create model Book - Create model Publisher - Add field publisher to book E:\day15>python2 manage.py migrate Operations to perform: Apply all migrations: admin, app01, auth, contenttypes, sessions Running migrations: Rendering model states... DONE Applying app01. 0002_auto_20160807_2043 ... OK |
会生成第三张表:
Django后台管理数据库。
首先在app01的admin.py下注册数据库表
1
2
3
4
5
6
|
import models # Register your models here. admin.site.register(models.UserInfo) admin.site.register(models.Author) admin.site.register(models.Book) admin.site.register(models.Publisher) |
创建后台用户:
python manage.py createsuperuser
登录后台并操作表:
定制表在后台返回字符串:
1
2
3
4
5
6
|
class Author(models.Model): first_name = models.CharField(max_length = 32 ) last_name = models.CharField(max_length = 32 ) email = models.EmailField() def __unicode__( self ): return "author: %s %s" % ( self .first_name, self .last_name) |
后台样式:
由于book是需要关联其他标的,所以在新增book数据时,关联字段是不能任意填写的,只能选择:
修改字段:
1
|
first_name = models.CharField(max_length = 32 ,null = True ) |
python manage.py makemigrations,python manage.py migrate
虽然数据库种这个字段可以为空,但是在Gjango后台还是不能以空插入数据:
要以空值插入数据,需要修改类中的表定义:
1
2
3
4
5
6
7
8
9
10
11
|
first_name = models.CharField(max_length = 32 ,null = True ,blank = True ) """ blank¶ Field.blank¶ If True, the field is allowed to be blank. Default is False. Note that this is different than null. null is purely database-related, whereas blank is validation-related. If a field has blank=True, form validation will allow entry of an empty value. If a field has blank=False, the field will be required. """ |
参考文档:
https://docs.djangoproject.com/en/1.10/ref/models/fields/
增、删、改、查(针对userinfo表)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
def db_h(request): # 增 # models.UserInfo.objects.create(username="ds",password="123",age=18) # 删 # models.UserInfo.objects.filter(username='ds').delete() # 改 # models.UserInfo.objects.filter(age=18).update(age=20) # models.UserInfo.objects.all().update(age=19) # 查 userlist_obj = models.UserInfo.objects. all () users = [] for user in userlist_obj: users.append(user.username) userstring = json.dumps(users) # models.UserInfo.objects.filter(username='ds') # models.UserInfo.objects.filter(age=18).first() return HttpResponse(userstring) |
模糊查找:参见官方文档。
https://docs.djangoproject.com/en/1.10/ref/models/querysets/
https://docs.djangoproject.com/en/1.10/topics/db/queries/
对于上面的多对多手动新增书籍:
1
2
3
4
5
6
7
8
|
E:\python27\day15>python2 manage.py shell >>> from datatime import datatime >>> p = models.Publisher.object.filter().first() >>> b = models.Book(bookname="OWASP",publish_date=datetime.now(),publisher=p) >>> b.save() >>> a = models.Author.objects.filter().first() >>> b.authors.add(a) >>> b.authors.remove(a) |
数据库取数据,并将数据传入html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
# app01.views def db_h(request): userlist_obj = models.UserInfo.objects. all () return render(request, "app01/tables.html" ,{ "li" :userlist_obj}) # templates.app01.tables.html <table> <tr> <th>姓名< / th> <th>密码< / th> <th>年龄< / th> < / tr> { % for item in li % } <tr> <td>{{ item.username}}< / td> <td>{{ item.password }}< / td> <td>{{ item.age }}< / td> < / tr> { % endfor % } < / table> |
2,6 引入静态文件
注意要是列表或元组,
2.7 数据提交。
对于POST请求需在setttings里把跨站请求注释掉。# 'django.middleware.csrf.CsrfViewMiddleware',
我们可以通过POST和GET方式提交,提交到后台的数据通过request.GET或request.POST方式取得,request,method是提交的方法,值为"POST"或"GET"。
('val:', <QueryDict: {u'username': [u'gg'], u'age': [u'21'], u'password': [u'rr']}>) , 这是在后台打印的POST方式的数据。我们可以通过request.POST["username"]获取username的值。
JSON数据转换:
1
2
3
4
5
6
7
8
|
# 将字典转为JSON格式(字符串)再发送给客户端 response_data_ok = { "status" : "ok" } return HttpResponse(json.dumps(response_data_ok)) # 客户端接收JSON格式的字符串后再反转为原来的格式 "success" :function(msg1){ msg = JSON.parse(msg1) } |
未完待续
2.8 Template渲染
基本语法:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
E:\day15>python2 manage.py shell Python 2.7 . 12 (v2. 7.12 :d33e0cf91556, Jun 27 2016 , 15 : 19 : 22 ) [MSC v. 1500 32 bit (Intel)] on win32 Type "help" , "copyright" , "credits" or "license" for more information. (InteractiveConsole) >>> >>> from django.template import Context,Template >>> t = Template( "My name is {{name}},I'am {{age}} years old" ) >>> c = Context({ "name" : "DS" , "age" : 18 }) >>> t.render(c) u "My name is DS,I'am 18 years old" >>> for i in [{ "name" : "DS" , "age" : 18 },{ "name" : "lj" , "age" : 20 }]: ... print (t.render(Context(i))) ... My name is DS,I'am 18 years old My name is lj,I'am 20 years old >>> # 深度变量查找1 >>> p = { "name" : "ow" , "age" : 20 } >>> t1 = Template( "My name is {{person.name}}" ) >>> c = Context({ 'person' :p}) >>> t1.render(c) u 'My name is ow' # 深度变量查找2 >>> t = Template( "My name is {{item.1}}" ) >>> c = Context({ "item" :[ "ds" , "lj" , "cc" ]}) >>> t.render(c) u 'My name is lj' # 深度查找3(类) >>> import datetime >>> d = datetime.date( 2016 , 8 , 7 ) >>> d.year 2016 >>> t = Template( "today is {{i.year}} {{i.month}} {{i.day}}" ) >>> c = Context({ "i" :d}) >>> t.render(c) u 'today is 2016 8 7' |
Template用于模板文件语法:
1
2
3
4
5
6
7
8
9
10
|
{ % for item in li % } <tr> <td>{{ item.username}}< / td> <td>{{ item.password }}< / td> <td>{{ item.age }}< / td> < / tr> { % endfor % } forloop.counter0 循环计数器 value}divisibleby: "2" 能被 2 整除 |
html继承和重写
模板app01/modle.html
1
2
3
4
5
6
7
|
< html > < body > < div >...</ div > {% block content %} {% endblock %} </ body > </ html > |
继承和重写app01/admin.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
{% extends "app01/modle.html" %} {% block content %} < div class="container"> < table class="table table-bordered table-hover "> < tr > < th >姓名</ th > < th >密码</ th > < th >年龄</ th > </ tr > {% for item in li %} < tr > < td >{{ item.username}}</ td > < td >{{ item.password }}</ td > < td >{{ item.age }}</ td > </ tr > {% endfor %} </ table > </ div > {% endblock %} |
导入
1
2
3
4
5
6
7
|
# weather.html < div > Weather </ div > # login.html {% include "app01/weather.html %} |