Python菜鸟之路：Django ModelForm的使用

一、简单使用案例

#views.py

#views.py

from django.shortcuts import render,HttpResponse

from app01 import models

from django import forms

from django.forms import fields as Ffields

from django.forms import widgets as Fwidgets

class UserInfoModelForm(forms.ModelForm):

    is_rmb = Ffields.CharField(widget=Fwidgets.CheckboxInput())

    class Meta:

        model = models.UserInfo

        fields = '__all__'

        # fields =  ['username','email']

        # exclude = ['username']

        labels = {

            'username': '用户名',

            'email': '邮箱',

        }

        help_texts = {

            'username': '...'

        }

        widgets = {

            'username': Fwidgets.Textarea(attrs={'class': 'c1'})

        }

        error_messages = {

            '__all__':{

            },

            'email': {

                'required': '邮箱不能为空',

                'invalid': '邮箱格式错误..',

            }

        }

        field_classes = {

            # 'email': Ffields.URLField

        }

        # localized_fields=('ctime',)

    def clean_username(self):

        old = self.cleaned_data['username']

        return old

def index(request):

    if request.method == "GET":

        obj = UserInfoModelForm()

        return render(request,'index.html',{'obj': obj})

    elif request.method == "POST":

        obj = UserInfoModelForm(request.POST)

        if obj.is_valid():

            # obj.save() 等效于下面的3条

            instance = obj.save(False)

            instance.save()  # 这样的话只会保存当前的类到数据库，并不会保存关联的多对多关系到U2G表中

            obj.save_m2m()  # 保存many to many的关系到数据库

        # print(obj.is_valid())

        # print(obj.cleaned_data)

        # print(obj.errors.as_json())

        return render(request,'index.html',{'obj': obj})

　　

　　

#models.py

from django.db import models

# Create your models here.

class UserType(models.Model):

    caption = models.CharField(max_length=32)

class UserGroup(models.Model):

    name = models.CharField(max_length=32)

class UserInfo(models.Model):

    username = models.CharField(max_length=32)

    email = models.EmailField()

    user_type = models.ForeignKey(to='UserType',to_field='id')

    u2g = models.ManyToManyField(UserGroup)

　　

　   总结： 从上边可以看到ModelForm用起来也是非常方便的，比如增加修改之类的操作。但是也带来额外不好的地方，model和model之间耦合了。如果不耦合的话，mf.save()方法也无法直接提交保存。 但是耦合的话使用场景通常局限用于小程序，写大程序就最好不用了