Django development 5-Quick preview of Django development knowledge points

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Django development

1. Review of knowledge points:

• Install Django

  pip install django
  

• Create a Django project

  >>> django-admin startproject mysite（项目名）
  

  Note: Pycharm can create. If created with Pycharm, remember to delete the DIR templates in settings.py.

• Create app & register

  >>>python manage.py startapp app01
  >>>python manage.py startapp app02
  >>>python manage.py startapp app03
  

  INSTALLED_APPS = [
      ...
      'app01.apps.App01Config'
  ]
  

  Note: Otherwise, when writing classes in models.py under the app, the table cannot be created in the database.

• Configure the static file path & template path (place it in the app directory).

• Configure database related operations (MySQL)

  • Third-party module (django3 version)

    pip install mysqlclient
    

  • First go to MySQL to create a database yourself.

  • Configure database connection settings.py

    DATABASES = {
            
            
        'default': {
            
            
            'ENGINE': 'django.db.backends.mysql',
            'NAME': 'gx_day16',  # 数据库名字
            'USER': 'root',
            'PASSWORD': 'root123',
            'HOST': '127.0.0.1',  # 那台机器安装了MySQL
            'PORT': 3306,
        }
    }
    

  • Written in models.py under app

    from django.db import models
    
    
    class Admin(models.Model):
        """ 管理员 """
        username = models.CharField(verbose_name="用户名", max_length=32)
        password = models.CharField(verbose_name="密码", max_length=64)
    
        def __str__(self):
            return self.username
    
        
    class Department(models.Model):
        """ 部门表 """
        title = models.CharField(verbose_name='标题', max_length=32)
    
        def __str__(self):
            return self.title
    

  • Execute two commands:

    >>>python manange.py makemigrations
    >>>python manange.py migrate
    

• In urls.py, routing (correspondence between URL and function).

• In views.py, view function, write business logic.

• templates directory, write HTML templates (including template syntax, inheritance, {% static 'xx'%})

• ModelForm & Form component, we develop the add, delete, modify and check function.

  • Generate HTML tags (generate default values)
  • Request data for verification.
  • Save to database (ModelForm)
  • Get error message.

• Cookies, Sessions, and user login information are saved.

• Middleware, which implements user authentication based on middleware, is based on: process_request.

• ORM operation //Modify the database

  models.User.objects.filter(id="xxx")//对id进行筛选
  models.User.objects.filter(id="xxx").order_by("-id")//排序
  

• Pagination component.

2.Ajax request

For related knowledge points, please see Django series development
. Link: Django series development
https://blog.csdn.net/hellow_xqs/category_12535125.html?spm=1001.2014.3001.5482

3. Order

class Order(models.Model):
    """ 订单 """
    oid = models.CharField(verbose_name="订单号", max_length=64)
    title = models.CharField(verbose_name="名称", max_length=32)
    price = models.IntegerField(verbose_name="价格")

    status_choices = (
        (1, "待支付"),
        (2, "已支付"),
    )
    status = models.SmallIntegerField(verbose_name="状态", choices=status_choices, default=1)
    admin = models.ForeignKey(verbose_name="管理员", to="Admin", on_delete=models.CASCADE)

When you want to get data from the database: object/dictionary

# 对象，当前行的所有数据。
row_object = models.Order.objects.filter(id=uid).first()
row_object.id
row_object.title

# 字典，{"id":1,"title":"xx"}
row_dict = models.Order.objects.filter(id=uid).values("id","title").first()

# queryset = [obj,obj,obj,]
queryset = models.Order.objects.all()

# queryset = [ {'id':1,'title':"xx"},{'id':2,'title':"xx"}, ]
queryset = models.Order.objects.all().values("id","title")

# queryset = [ (1,"xx"),(2,"xxx"), ]
queryset = models.Order.objects.all().values_list("id","title")

summary

So far, the addition, deletion, modification and check of pages have been implemented based on Ajax + dialog box.

• Forms can be added, deleted, modified and checked.
• Ajax, realize adding, deleting, modifying and checking.

chart

• highchart, abroad.
• echarts, domestic.

Chart learning links: Link: Reference documents
More reference documents: https://echarts.apache.org/handbook/zh/get-started