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_displaypublish = 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.titleclass 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.nameclass 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

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)
]

#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})