关于form组件的补充-------formChoice

form组件的Choice字段

　　还是基于出版社和书的模型来详解

　　models.py(模型)

from django.db import models


# Create your models here.
class Book(models.Model):
    title = models.CharField(max_length=32)
    pub_date = models.DateField()
    price = models.DecimalField(max_digits=5, decimal_places=2)
    state=models.IntegerField(choices=((1,'已出版'),(2,'未出版')),default=1)  #在数据库存储是以数字存储的,怎么取值?book是类的对象--book.get_state_display
    publish = models.ForeignKey(to="Publish", to_field="id", on_delete=models.CASCADE, null=True)
    authors = models.ManyToManyField("Author", db_table="book2authors")  # 创建关系表

    def __str__(self):
        return self.title


class Publish(models.Model):
    name = models.CharField(max_length=32)
    city = models.CharField(max_length=32)
    email = models.CharField(max_length=32)

    def __str__(self):
        return self.name


class Author(models.Model):
    name = models.CharField(max_length=32)
    age = models.IntegerField()
    gender=models.IntegerField(choices=((1,'男'),(2,'女'),),default=1)#在数据库存储是以数字存储的,怎么取值?book是类的对象--book.get_gender_display

　　urls.py(路径分发)

urlpatterns = [
    path('admin/', admin.site.urls),
    path('books/', views.books, name='books'),
    path('addbooks/', views.addbooks, name='addbooks'),
    re_path('delbooks/(d+)', views.delbooks),
    re_path('editbooks/(d+)', views.editbooks)
]

　　view.py(视图函数)

#为Book这个模型创建forms,为了渲染数据和校验使用,所以这个类的字段必须和模型类有个逻辑上的关系

class BookForm(forms.Form):
    title=forms.CharField(max_length=32)
    price= forms.DecimalField(max_digits=5,decimal_places=2)
    pub_date = forms.DateField()
    state=forms.ChoiceField(choices=((1,'已出版'),(2,'未出版')))          #选择项,用的最多
    publish=forms.ModelChoiceField(models.Publish.objects.all())         #一对多
    authors=forms.ModelMultipleChoiceField(models.Author.objects.all())  #多对多

　　#对于publish和author这两个一对多和多对多的字段也不用考虑那么多直接用formChoice字段,然后把所有的对象取出来赋值到里面就行


#查看书籍
def books(request):
    booklist = models.Book.objects.all()
    return render(request, 'books.html', {'booklist': booklist})


#添加书籍

def addbooks(request):
    # 通过form/ModelForm以及校验标签渲染字段以及输入框
    if request.method == 'POST':
        form = Bookform(request.POST)
        if form.is_valid():
            form.save()
            return redirect('/books/')
        else:
            return render(request, 'addbooks.html', {'form': form})
    else:
        # form=BookForm()   #form组件形式,根据字段选择不同的字段类型
        return render(request, 'addbooks.html', {'form': form})

#编辑书籍

def editbooks(request, editbook_id):
    editbook=models.Book.objects.filter(pk=editbook_id).first()
    if request.method == 'POST':
        form=BookForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect('/books/')
        else:
            return render(request,'editbooks.html',{'form':form})
    else:
        form=BookForm(edit_book)
        return render(request,'editbooks.html',{'form':form})