Python 【第十三章】 Django 之 FORM

不涉及数据库存储数据例一：FORM 实现页面下拉选择框：

url.py

from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
    # url(r'^admin/', admin.site.urls),
    url(r'^index/',views.index),
]

views.py

from django.shortcuts import render
from django.shortcuts import HttpResponse
from app01 import models
from django import forms

class Indexform(forms.Form):
    c = {
        (1,'CEO'),
        (2,'COO')
    }
    user_type_id = forms.IntegerField(widget=forms.Select(choices=c))

def index(request):
    form = Indexform()
    return render(request,'index.html',{'form':form})

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<h1>index</h1>
{{ form.user_type_id }}

</body>
</html>

涉及数据库存储数据例二：通过models.py 一对一外表关联方式来实现

models.py

from django.db import models

# Create your models here.

class UserType(models.Model):
    caption = models.CharField(max_length=16)

class UserInfo(models.Model):
    user = models.CharField(max_length=32)
    pwd = models.CharField(max_length=32)
    user_type = models.ForeignKey('UserType')

创建数据库表执行以下两个语句：

python manage.py makemigrations
python manage.py migrate

views.py 通过循环来生成数据

from django.shortcuts import render
# from django.shortcuts import HttpResponse
from app01 import models
from django import forms

class Indexform(forms.Form):
    c = {
         (1,'CEO'),
         (2,'COO')
     }
   
    user_type_id = forms.IntegerField(widget=forms.Select(choices=c))

def index(request):
    for i in range(10):
        models.UserType.objects.create(caption='CE'+str(i))
    c = models.UserType.objects.all().count()
    print(c)
    form = Indexform()
    return render(request,'index.html',{'form':form})

生成数据后，修改viiews.py

from django.shortcuts import render
# from django.shortcuts import HttpResponse
from app01 import models
from django import forms

class Indexform(forms.Form):
    # c = {
    #     (1,'CEO'),
    #     (2,'COO')
    # }
    c = models.UserType.objects.all().values_list('id','caption')  #该名在数据库有数据后出现，就不会有出错如果数据库在没有数据时，该语句查不到数据，会报错
    user_type_id = forms.IntegerField(widget=forms.Select(choices=c))

def index(request):
    # for i in range(10):
    #     models.UserType.objects.create(caption='CE'+str(i))
    # c = models.UserType.objects.all().count()
    # print(c)
    form = Indexform()
    return render(request,'index.html',{'form':form})

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<h1>index</h1>
{{ form.user_type_id }}

</body>
</html>

遇到问题，如果在数据库中继续添加新数据，会出现页面没有显示新数据，如果显示，需要重启django

以下方法是解决上述问题

views.py

from django.shortcuts import render
from django.shortcuts import HttpResponse
from app01 import models
from django import forms

class Indexform(forms.Form):
    # c = {
    #     (1,'CEO'),
    #     (2,'COO')
    # }
    c = models.UserType.objects.all().values_list('id','caption')  # 类中静态字段原理，由类直接调用
    user_type_id = forms.IntegerField(widget=forms.Select(choices=c))
    def __init__(self,*args, **kwargs):
        # 父类构造方法：1、获取所有静态字段   2、fields = []
        super(Indexform, self).__init__(*args, **kwargs)
        # print(self.fields['user_type_id'].widget.choices)
        self.fields['user_type_id'].widget.choices = models.UserType.objects.all().values_list('id','caption')


def index(request):
    # for i in range(10):
    #     models.UserType.objects.create(caption='CE'+str(i))
    # c = models.UserType.objects.all().count()
    # print(c)
    form = Indexform()
    return render(request,'index.html',{'form':form})

def add_user_type(request):
    q = request.GET.get('q', None)
    if q:
        models.UserType.objects.create(caption=q)
    return HttpResponse(q)

url.py

from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
    # url(r'^admin/', admin.site.urls),
    url(r'^index/',views.index),
    url(r'^add_user_type/',views.add_user_type),
]

add_user_type.html

测试添加数据

http://127.0.0.1:8000/add_user_type/?q=yangjian

实现实时添加新数据