Python3 Web开发框架-Django学习笔记（二）创建应用程序

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python web开发学习心得，原创文章，转载请注明出处

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1.创建应用程序

~/Desktop/python/leaning_log ᐅ source ll_env/bin/activate
(ll_env) ~/Desktop/python/leaning_log ᐅ python manage.py startapp learning_logs
(ll_env) ~/Desktop/python/leaning_log ᐅ ls
db.sqlite3    leaning_log   learning_logs ll_env        manage.py
(ll_env) ~/Desktop/python/leaning_log ᐅ ls learning_logs
__init__.py admin.py    apps.py     migrations  models.py   tests.py    views.py
(ll_env) ~/Desktop/python/leaning_log ᐅ

2.定义模型，创建一个名为Topic的类

打开文件models.py,导入modes模块
models.py
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rom django.db import models

# Create your models here.

class Topic(models.Model):
    """用户学习的主题"""
    text = models.CharField(max_length = 200)
    date_added = models.DateTimeField(auto_now_add=True)

    #python2.7调用__unicode__()代替__str__()
    def __str__(self):
        '''返回摸醒的字符串展示'''
        return self.text

3.激活模型

1.打开settings.py(learning_log/learning_log里面)

2.找到函数
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

3.添加应用进去
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    
    #我的应用
    'learning_logs'
]

4.修改数据库，使其能存储Topic相关信息

1.命令makemigrations让Django确定如何修改数据库
(ll_env) ~/Desktop/python/leaning_log ᐅ python3 manage.py makemigrations learning_logs
Migrations for 'learning_logs':
  learning_logs/migrations/0001_initial.py:
    - Create model Topic
(ll_env) ~/Desktop/python/leaning_log ᐅ

2.让Django提我们修改数据库
(ll_env) ~/Desktop/python/leaning_log ᐅ python3 manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, learning_logs, sessions
Running migrations:
  Applying learning_logs.0001_initial... OK
(ll_env) ~/Desktop/python/leaning_log ᐅ

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小结：每当需要修改管理的数据时：

1.修改models.py
2.对learnin_logs调用makemigrations
3.让Django迁移项目

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3.创建超级用户

用户名可用默认，邮箱可为空
(ll_env) ~/Desktop/python/leaning_log ᐅ python manage.py createsuperuser
Username (leave blank to use 'jinyulong'):
Email address:
Password:
Password (again):
Superuser created successfully.
(ll_env) ~/Desktop/python/leaning_log ᐅ

4.向管理网站注册模型

from django.contrib import admin
from learning_logs import  Topic

admin.site.register(Topic)

5.运行chrome查看效果

管理员登录.png

管理员控制台.png

6.添加主题

点击Topics的Add,看见输入框，点Save，就保存了刚刚创建的主题