django怎么直接使用数据库?Django教程——01安装使用Django教程——02连接初始化数据库，今天小编就来说说关于django怎么直接使用数据库?下面更多详细答案一起来看看吧!
django怎么直接使用数据库
Django教程——01安装使用
Django教程——02连接初始化数据库
接着上文连接好数据库后，下面讲下如何通过Django将工程里实体对象生成数据库表
一、定义实体
在polls应用下创建数据库实体
其中Django数据库字段属性设置教程 https://docs.djangoproject.com/en/4.0/ref/models/fields/ Model field reference | Django documentation | Django
polls/models.py
from django.db import models# Create your models here.class Question(models.Model): question_text=models.CharField(max_length=200) pub_date=models.DateTimeField('date published') def __str__(self): return self.question_textclass Choice(models.Model): question=models.ForeignKey(Question,on_delete=models.CASCADE) choice_text=models.CharField(max_length=200) votes=models.integerField(default=0) def __str__(self): return self.choice_text
二、使用实体对象
1、在项目settings.py里引入应用
mysite/settings.py
INSTALLED_APPS = [ 'polls.apps.PollsConfig', 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles',]
2、初始化模型对象
python manage.py makemigrations polls
执行该命令后，就会在polls/migrations/0001_initial.py文件下生成实体对象代码，用于生成数据库表用
3、生成建表sql
python manage.py sqlmigrate polls 0001
执行结果如下
BEGIN;---- 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);---- Create model Choice--CREATE TABLE "polls_choice" ( "id" serial NOT NULL PRIMARY KEY, "choice_text" varchar(200) NOT NULL, "votes" integer NOT NULL, "question_id" integer NOT NULL);ALTER TABLE "polls_choice" ADD CONSTRAINT "polls_choice_question_id_c5b4b260_fk_polls_question_id" FOREIGN KEY ("question_id") REFERENCES "polls_question" ("id") DEFERRABLE INITIALLY DEFERRED;CREATE INDEX "polls_choice_question_id_c5b4b260" ON "polls_choice" ("question_id");COMMIT;
4、同步建表语句到数据库
python manage.py migrate
执行完后，数据库就会增加上面两张表
三、shell操作
执行shell命令
python manage.py shell
就可以通过控制台进行编写调用模型的api
>>> 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