Supplement: emailField is actually charField
models中所有的字段类型都没有实际的约束作用
但是虽然写在models中没有限制作用,但是它们对于校验性组件
是非常有用的Check Line Components
1. Choices parameter
The choices parameter is a parameter commonly used in models, in this case it is the parameter in IntegerField().
1 Introduction : How does gender exist? Usually stored in numbers . Figure 1
# 图1
username gender
jason 1Others that require "things that require the choices parameter": Figure 2
# 图2
用户性别
用户学历
工作状态
客户来源
是否结婚This case uses Django's default database sqlite:
Operation method:
The sqlite database can be used directly! make migration and migrate
2Django test environment (review)
import os
if __name__ == "__main__":
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "day57.settings")
import django
django.setup()
from app01 import models
#下面写要测试的内容，比如：
user_obj = models.User.objects.filter(pk=7).first()
# print(user_obj.gender)
print(user_obj.get_gender_display())
"""
只要是choices字段 在获取数字对应的注释 固定语法
get_choices字段名_display()
"""4choices writing: take age as an example
4.1models storage
#models存
choices =((1,'男'),(2,'女'),(3,'保密'))
gender = models.InteferField(choices = choices)
# 现在，存到数据库里是数字4.2 test take
# 固定格式
get_字段名_display()
# 比如
user_obj = models.User.objects.filter(pk=7).first()
user_obj.get_gender_display()
# 存没有罗列迟来的数字
不会报错 还是展示数字There is no corresponding relationship to take out the number!
Gentlemen love fortune, in a proper way
There is no free lunch
2. MTV and MVC model
To understand the knowledge points is to abbreviate the English words. All web frameworks are MVC models .
The django framework calls itself an MTV framework: M:models; T:templates;V:views
MVC: M: models; V: views; C: controller controller (urls)
Note: There may be matching errors in the regular expression of the url, so write the regular expression more accurately
Three, ajax (key)
Specific: Asynchronous commit partial refresh
a标签href属性 GET请求
浏览器窗口输入url GET请求
form表单 GET/POST
ajax GET/POSTAjax is a new way to send get and post requests. And can send json format (form form does not support json format)
First of all, the technology of ajax is in js, but the native js operation of ajax is cumbersome. In order to improve efficiency, we directly use the jQuery packaged version of ajax
The biggest advantage of AJAX is that you can exchange data with the server and update part of the web page content without reloading the entire page.
(This feature gives the user the feeling that the request and response process is completed unknowingly)
case snooping ajax
Reminder: post request must annotate the content of setigns
def index(request):
# print(request.is_ajax()) # 用来判断当前请求方式是否是ajax请求,打开网页默认是GET请求，走index.html
if request.is_ajax():
if request.method == 'POST': # ajax请求有两种请求方法
# print(request.POST)<QueryDict: {'i1': ['213'], 'i2': ['34']}>，ajax请求提交的数据全部在request.POST中
i1 = request.POST.get('i1')
i2 = request.POST.get('i2')
# 后端获取的前端数据 都是字符串格式
res = int(i1) + int(i2)
return HttpResponse(res) #三剑客此时都会返回到html里
return render(request,'index.html')
#前端
$('#b1').on('click',function () {
alert(123)
// 点击按钮 朝后端发送post请求
$.ajax({
url:'', // 控制发送给谁 不写就是朝当前地址提交
type:'post', // 发送方式是post请求
data:{'i1':$('#i1').val(),'i2':$('#i2').val()}, // 发送的数据
success:function (data) { // data形参就是后端返回的异步提交的结果，通常是一个字典
// data自动转成自定义对象，可以使用点点点的方法，
// if (data.code ==1000){
逻辑
}
// 将后端计算好的结果 通过DOM操作 渲染到第三个input矿中
$('#i3').val(data)
}
})Four, contentType front-end and back-end transmission data encoding format
4.1 Front-end and back-end transmission data encoding format
1.urlencoded》》》name=SDF&password=FDS
2.formdata》》》看不到编码格式；传文件也支持传普通键值(name=jason&pwd=123&hobby=read)
3.application/json # json格式数据(form表单是无法发送 4.1.1 form form , the default encoding format is urlencoded
form form can upload files
How does the django backend handle different encoding formats?
只要是符合urlencoded编码格式 都会被后端自动获取并解析放到request.POST中
如果是符合formdata那么文件会自动被解析放到request.FILES中
如果是json格式 后端默认不解析 以二进制的形式就放在request.body你可以自己手动处理即可
4.1.3 ajax submission data : json and files
The default data submission method of ajax is also urlencoded, and the data sent by ajax in json format is placed in request.body
print(,request.body)b'{"name":"wx","password":"123"}'JSON format ajax needs to manually process JSON format data
$('#b1').on('click',function () {
alert(123)
// 点击按钮 朝后端发送post请求
$.ajax({
url:'', // 控制发送给谁 不写就是朝当前地址提交
type:'post', // 发送方式是post请求
data:JSON.stringify({'username':'jason','password':123}), // 发送的数据
// 告诉后端你这次的数据是json格式
contentType:'application/json', //
success:function (data) { // data形参用来接收异步提交的结果
alert(data)
// 将后端计算好的结果 通过DOM操作 渲染到第三个input矿中
$('#i3').val(data)
}
})
// {)ajax file transfer:
Required: for
// ajax传输文件
$('#b1').on('click',function () {
// ajax传输文件 建议使用内置对象formdata
var formData = new FormData(); // 既可以传普通的键值对 也可以传文件
// 添加普通键值
formData.append('username','jason');
formData.append('password','123');
// 传文件
// 如何获取文件标签所存储的文件对象? 固定语法
// 1.先用jQery查找到存储文件的input标签
// 2.将jQuery对象转成原生js对象
// 3.利用原生js对象的方法 .files[0]获取到标签内部存储的文件对象
// 4.一定要指定两个参数都为false
formData.append('my_file',$('#d1')[0].files[0]);
$.ajax({
url:'', // 控制发送给谁 不写就是朝当前地址提交
type:'post', // 发送方式是post请求
data:formData, // 发送的数据
// ajax发送文件需要指定两个额外的参数
processData:false, // 告诉前端不要处理数据
contentType:false, // 不适用任何编码 因为formdata对象自身自带编码 django后端也能够识别formdata对象
success:function (data) { // data形参用来接收异步提交的结果
{#alert(data)#}
// 将后端计算好的结果 通过DOM操作 渲染到第三个input矿中
$('#i3').val(data)
}
})
})5. Serialization component: serializers: Display database data and rendering dictionary on the front-end page
Requirement: Organize all data into a json-compliant dictionary and send it to the front-end page
def reg(request):
user_list = models.User.objects.all()
user_l=[]
for i in user_list:
user_l.append(json.dumps({'uername':i.name,'age':i.age,'gender':i.get_gender_display()}))
return render(request,'index.html',locals())These code serializers do it for you. And he integrates more data than you
def reg(request):
user_list = models.User.objects.all()
res = serializers.serialize('json',user_list)
return render(request,'index.html',locals())# .而且他整合的数据比你多
[{"model": "app01.user",
"pk": 1,
"fields": {"name": "\u5434\u9521",
"age": 23, "gender": 1}},
{"model": "app01.user",
"pk": 2,
"fields": {"name": "\u738b\u5927\u9524", "age": 18, "gender": 2}},
{"model": "app01.user",
"pk": 3,
"fields": {"name": "\u9f50\u5929\u5927\u5723", "age": 99, "gender": 3}}]06 Ajax combined with sweetalert plugin
sweetalert makes popovers a little nicer. Need to download: we just need to use the dist folder inside
Bulk insert data 1.:
1. 这种插入速度非常慢
for i in range(1000):
models.Book.objects.create(title='第%s本书'%i)
2.
l = []
for i in range(10000):
l.append(models.Book(title='第%s本书'%i))
models.Book.objects.bulk_create(l) # 批量插入数据page display of user data
Note: {{user.get_gender_display}} in the html file does not need to add parentheses here, it will add
custom pager
You don't need to write anything, you just need to know the idea
Condition: quertest supports slicing
The object when the front-end for loop loops! , cannot {% for i inrange(10)%}, there is no range parameter in the front end
book_list = models.Book.objects.all()
current_page = request.GET.get("page",1)
all_count = book_list.count()
page_obj=Pagination(current_page=current_page,all_count=all_count,per_page_num=10,pager_count=5)
page_queryset = book_list[page_obj.start:page_obj.end]
前端代码
{% for book in page_queryset %}
<p>{
{ book.title }}</p>
{% endfor %}
{
{ page_obj.page_html|safe }}Front-end import file
<script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
{% load static %}
<link rel="stylesheet" href="{% static 'bootstrap-3.3.7-dist/css/bootstrap.min.css' %}">
<link rel="stylesheet" href="{% static 'dist/sweetalert.css' %}">
<script src="{% static 'bootstrap-3.3.7-dist/js/bootstrap.min.js' %}"></script>
<script src="{% static 'dist/sweetalert.min.js' %}"></script>Reprinted in: https://www.cnblogs.com/ZDQ1/p/11592357.html