Django对数据库进行增加以及查询显示功能实现

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准备

1.创建Django框架
2.安装Django服务与mysqlclient服务
3.创建子应用
4.开启数据库服务,并创建一个接下来需要用的新数据库
(详细内容请见前几章节Django创建第一个应用程序
Django连接数据库)

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一、初始化应用层下的代码

1.settings.py

主要配置INSTALLED_APPS 和DATABASES 数据库服务

"""
Django settings for 增查 project.

Generated by 'django-admin startproject' using Django 3.1.7.

For more information on this file, see
https://docs.djangoproject.com/en/3.1/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.1/ref/settings/
"""

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'it38^ojb01ua^x%o8je*(!8udch8r!!!@p74^ra%3%(8jhq2%y'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'stu'
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = '增查.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [BASE_DIR / 'templates']
        ,
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = '增查.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'student',# 你自己的数据库名
        'USER': 'root',# 用户名
        'PASSWORD': 'root',# 密码
        'HOST': 'localhost',# 本地ip
        'PORT': 3306,# 端口号
    }
}


# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/

STATIC_URL = '/static/'

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2.urls.py

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('stu/', include('stu.urls')),# 子应用
]

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3.注意

以上几步有哪里不懂的小伙伴可以看一下Django创建第一个应用程序
Django连接数据库

二、子应用层

1.urls.py

from django.urls import path

from stu import views

urlpatterns = [
    path('login/', views.login),
]
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2.views.py

不懂的小伙伴可以观看注释内的文字内容

from django.http import HttpResponse
from django.shortcuts import render

from stu.models import Student


def login(request):
    # 判断请求方式
    if (request.method == 'GET'):
        # 如果是get请求直接返回页面
        return render(request, 'login.html')
    else:
        # 如果是post请求做表单验证
        sname = request.POST.get('sname')
        spwd = request.POST.get('spwd')
        # sigt是获取注册按钮,前端点击注册按钮就有返回值,没有点击就为空
        sigt=request.POST.get('sigt')
        # 获取数据库表中所有元素.相当于sql语句:select * from student
        stus = Student.objects.all()
        # 先判断是不是注册按钮
        if(sigt != None):
            # 是注册按钮就直接写入数据库
            Student(sname=sname, spwd=spwd).save()
            return HttpResponse('<h1>已为您注册成功!</h1>')
        # 如果是登录按钮,就遍历数据库表中的内容
        for i in stus:
            if (i.sname == sname and i.spwd == spwd):
                return render(request, 'index.html', {'stus': stus})
        else:
            return HttpResponse('<h1>请先注册!!</h1>')


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3.models.py

from django.db import models

class Student(models.Model):
	# 这里是模型类,这里跟数据库列名要保持一致
    sname=models.CharField(max_length=10)
    spwd=models.CharField(max_length=10)
    class Meta:
        db_table='stu'
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三.templates中html页面

1.login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/stu/login/" method="post">
        {% csrf_token %}
        用户名:<input type="text" name="sname"><br/>
        密&emsp;码:<input type="password" name="spwd"><br/>
        <input type="submit" value="登录">&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;
        <input type="submit" value="注册" name="sigt">
    </form>

</body>
</html>
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2.index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <table border="1" cellspacing="1" cellpadding="1" width="300px">
        <tr>
            <th>编号</th>
            <th>用户名</th>
            <th>密码</th>
        </tr>
{#        Django框架可以在html页面中直接写Python代码,使用方式为{% 代码 %}#}
        {% for i in stus %}
            <tr>
{#                在页面中使用Python代码输出变量#}
                <td>{{ i.id }}</td>
                <td>{{ i.sname }}</td>
                <td>{{ i.spwd }}</td>
            </tr>
        {% endfor %}
    </table>

</body>
</html>
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3.模板语法

模板语法：
｛%%｝
循环:
{% for 变量 in 序列 %}
{% endfor %}
注释:
{# #}
判断:
{% if: %}
{% elif: %}
{% endif %}
模板变量：
｛｛｝｝

四.生成迁移文件与执行迁移文件

生成迁移文件: python manage.py makemigrations
执行迁移文件: python manage.py migrate stu

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五.执行效果图[简陋版]

六.小结

本章使用Django框架实现了对数据库的增加以及查询功能的实现,和html中的少量模板语法,实现方法不只这一种,各位感兴趣的小伙伴,可以去试一试.
有哪里不足或者有更好的建议,欢迎留言吐槽,有哪里不懂的小伙伴可以私信我,我会一一答复,感谢认可,感谢支持!