四、Django学习：定义后台与修改模型

默认Django后台管理页面无法看出标题，需要进行一定的配置。

在修改模型(增加、删除字段)时，需要设置默认值，而且需要更新数据库使应用生效。

一、定制后台页面

• 修改article models.py文件

from django.db import models

# Create your models here.

class Article(models.Model):
    title = models.CharField(max_length=40)
    content = models.TextField()
    
    def __str__(self):
        return "<Article:%s>" % self.title

启动服务python manage.py runserver，访问localhost:8000/admin，输入账号密码。

要让内容显示出来，不建议在models.py文件中进行修改，而是应该在admin.py文件中进行修改。

• 修改article admin.py文件

from django.contrib import admin
from .models import Article

# Register your models here.
class ArticleAdmin(admin.ModelAdmin):
    # 显示字段
    list_display = ("id", "title", "content")
   
admin.site.register(Article, ArticleAdmin)

重新启动服务，进入后台页面。

调整显示顺序

修改article admin.py文件

from django.contrib import admin
from .models import Article

# Register your models here.

class ArticleAdmin(admin.ModelAdmin):
    list_display = ("id", "title", "content")
    # 正序排列，如果需要按相反顺序，在前面加-号，如ordering = ("-id", )
    ordering = ("id", "title", "content")

admin.site.register(Article, ArticleAdmin)

• 另外一种注册的方式

修改article admin.py文件

from django.contrib import admin
from .models import Article

# Register your models here.
@admin.register(Article)
class ArticleAdmin(admin.ModelAdmin):
    list_display = ("id", "title", "content")
    ordering = ("id", "title", "content")
    

保存刷新，结果一样。

---

二、修改模型

修改article models.py文件

from django.db import models
#from django.utils import timezone
from django.contrib.auth.models import User

# Create your models here.

class Article(models.Model):
    title = models.CharField(max_length=40)
    content = models.TextField()
    #created_time = models.DateTimeField(default=timezone.now)
    created_time = models.DateTimeField(auto_now_add=True)
    last_updated_time = models.DateTimeField(auto_now=True)
    author = models.ForeignKey(User, on_delete='models.DO_NOTHING', default=1)
    is_deleted = models.BooleanField(default=False)
    readed_num = models.IntegerField(default=0)
    
    def __str__(self):
        return "<Article:%s>" % self.title

修改article admin.py文件

from django.contrib import admin
from .models import Article

# Register your models here.
@admin.register(Article)
class ArticleAdmin(admin.ModelAdmin):
    list_display = ("id", "title", "author", "content", "is_deleted", "created_time", "last_updated_time")
    ordering = ("id", )

#admin.site.register(Article,ArticleAdmin)

执行数据库迁移及迁移应用操作，重启服务

​ 标识is_deleted用法：被标识为删除的文章并没有实际删除，可以通过修改views.py文件来过滤显示，让127.0.0.1:8000/article只显示未被标记删除的文章列表。

• 修改views.py文件

from django.shortcuts import render,get_object_or_404,render_to_response
from django.http import HttpResponse,Http404
from .models import Article

# Create your views here.

def article_detail(request, article_id):
    #article = Article.objects.get(id=article_id)
    article = get_object_or_404(Article,pk=article_id)
    context = {}
    context['article_obj'] = article
    return render_to_response('article_detail.html', context)
    
def article_list(request):
    # 使用Article.objects.filter()来进行过滤
    article_list = Article.objects.filter(is_deleted=False)
    context = {}
    context['article_list_obj'] = article_list
    return render_to_response('article_list.html', context)

重新执行迁移，重启服务，可以看到标记为删除的文章标题未显示出来。