【django基础】django相关常用命令_django命令

django相关常用命令

1. 创建项目

django-admin startproject mysite
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执行完命令后，会生成以下文件

mysite/
    manage.py
    mysite/
        __init__.py
        settings.py
        urls.py
        asgi.py
        wsgi.py
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2. 服务启动

python manage.py runserver
# 可以指定ip和端口号
python manage.py runserver 8080
python manage.py runserver 0:8000
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3. 创建应用

python manage.py startapp polls
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这将会创建一个 polls 目录，它的目录结构大致如下：

polls/
    __init__.py
    admin.py
    apps.py
    migrations/
        __init__.py
    models.py
    tests.py
    views.py
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4. 创建表（模型）

4.1 创建相关表

这个migrate命令检查INSTALLED_APPS 设置，为其中的每个应用创建需要的数据表。 只会迁移INSTALLED_APPS中的

python manage.py migrate
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4.2 迁移表模型

迁移表模型，需要指定app名称

python manage.py makemigrations polls
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通过运行 makemigrations 命令，Django 会检测你对模型文件的修改（在这种情况下，你已经取得了新的），并且把修改的部分储存为一次 迁移。

注意

1. makemigrations会在当前目录下生成一个migrations文件夹，该文件夹的内容就是数据库要执行的内容
   python manage.py makemigrations
2. migrate就是执行之前生成的migrations文件，这一步才是操作数据库的一步
   python manage.py migrate
   Django每次更新模型都需要执行以上两步，需要注意的是Django模型增加内容需要设定变量的初始值，否则会在第一步出现问题

4.3 生成表的sql

python manage.py sqlmigrate polls 0001
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返回对应的sql

BEGIN;
--
-- Create model Choice
--
CREATE TABLE "polls_choice" (
    "id" serial NOT NULL PRIMARY KEY,
    "choice_text" varchar(200) NOT NULL,
    "votes" integer NOT NULL
);
--
-- Create model Question
--
CREATE TABLE "polls_question" (
    "id" serial NOT NULL PRIMARY KEY,
    "question_text" varchar(200) NOT NULL,
    "pub_date" timestamp with time zone NOT NULL
);
--
-- Add field question to choice
--
ALTER TABLE "polls_choice" ADD COLUMN "question_id" integer NOT NULL;
ALTER TABLE "polls_choice" ALTER COLUMN "question_id" DROP DEFAULT;
CREATE INDEX "polls_choice_7aa0f6ee" ON "polls_choice" ("question_id");
ALTER TABLE "polls_choice"
  ADD CONSTRAINT "polls_choice_question_id_246c99a640fbbd72_fk_polls_question_id"
    FOREIGN KEY ("question_id")
    REFERENCES "polls_question" ("id")
    DEFERRABLE INITIALLY DEFERRED;

COMMIT;
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5. 交互式 Python 命令行

python manage.py shell
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这个就可以对模型（表）进行访问了

>>> from polls.models import Choice, Question  # Import the model classes we just wrote.

# No questions are in the system yet.
>>> Question.objects.all()
<QuerySet []>

# Create a new Question.
# Support for time zones is enabled in the default settings file, so
# Django expects a datetime with tzinfo for pub_date. Use timezone.now()
# instead of datetime.datetime.now() and it will do the right thing.
>>> from django.utils import timezone
>>> q = Question(question_text="What's new?", pub_date=timezone.now())

# Save the object into the database. You have to call save() explicitly.
>>> q.save()

# Now it has an ID.
>>> q.id
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# Access model field values via Python attributes.
>>> q.question_text
"What's new?"
>>> q.pub_date
datetime.datetime(2012, 2, 26, 13, 0, 0, 775217, tzinfo=<UTC>)

# Change values by changing the attributes, then calling save().
>>> q.question_text = "What's up?"
>>> q.save()

# objects.all() displays all the questions in the database.
>>> Question.objects.all()
<QuerySet [<Question: Question object (1)>]>
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6. Django管理页面

6.1 创建管理员账号

python manage.py createsuperuser
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