使用Django框架实现对数据库的增删改查


文章目录

  • 使用Django框架实现对数据库的增删改查
  • 准备
  • 一、配置settings.py文件
  • 二、配置urls.py文件
  • 1.初始化应用下的urls.py
  • 2.子应用下的urls.py
  • 三.创建模型类models.py
  • 1.使用逆向创建数据库模型
  • 2.手动编写模型类
  • 四.编写views.py视图层文件
  • 五.在templates编写前端html页面
  • 1.主页面
  • 2.修改页面
  • 3.查询and详情页面
  • 六.效果图
  • 七.小结


准备

[小白必看]
1.创建Django程序,安装Django服务.点击跳转 2.安装mysqlclient服务,配置数据库.点击跳转
3.启动mysql服务,创建一个要用的数据库.
4.创建子应用,创建并执行迁移文件.走你

一、配置settings.py文件

"""
Django settings for 增删改查 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 = 'a#cmjl*d09^fvgya7_*yji$nbr=$wh!fue@en*-ey)+x7p&$$r'

# 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 = '增删改查.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 = '增删改查.wsgi.application'


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

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'student',# 数据库名称
        '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/'

二、配置urls.py文件

1.初始化应用下的urls.py

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

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

2.子应用下的urls.py

from django.urls import path
from stu import views

urlpatterns = [
    path('seleAll/', views.seleAll),
    path('delStu/', views.delStu),
    path('updStu/', views.updStu),
    path('seleOne/', views.seleOne),
    path('seleStu/', views.seleStu),

]

三.创建模型类models.py

1.使用逆向创建数据库模型

在terminal控制台中输入:

python manage.py inspectdb>stu/models.py
关键字:inspectdb>
stu是我的子应用名称
models.py是存放模型类的文件名称

2.手动编写模型类

from django.db import models


class Stu(models.Model):
    id = models.AutoField(primary_key=True)
    sname = models.CharField(max_length=10)
    spwd = models.CharField(max_length=10)

    class Meta:
        managed = False
        db_table = 'stu'

    def __str__(self):
        return f'id:{self.id},sname:{self.sname},spwd={self.spwd}'

四.编写views.py视图层文件

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

from stu.models import Stu


# 查询所有
def seleAll(request):
    # 查询所有,相当于select * from stu
    Stus = Stu.objects.all()
    # 将获得的数据以对象的形式返回到页面中
    return render(request, 'seleAll.html', {'stus': Stus})


# 根据id删除单个数据
def delStu(request):
    sid = request.GET.get('sid')
    if sid is not None:
        # 删除
        Stu.objects.get(id=sid).delete()
        # 重定向
        return redirect('/stu/seleAll/')
    else:
        return HttpResponse('<h1>删除失败!!</h1>')


# 根据id修改
def updStu(request):
    if request.method == 'GET':
        # get请求就是在页面点击进来的
        sid = request.GET.get('sid')
        stu = Stu.objects.get(id=sid)
        return render(request, 'updateStu.html', {'stu': stu})
    else:
        # post请求就是表单提交修改后的数据
        sid = request.POST.get('sid')
        sname = request.POST.get('sname')
        spwd = request.POST.get('spwd')
         # filter是过滤
        st = Stu.objects.filter(id=sid).update(sname=sname, spwd=spwd)
        if st==1:
            return redirect('/stu/seleAll')
        else:
            return HttpResponse('<h1>修改失败!!</h1>')

# 详情页查询
def seleOne(request):
    # 将查询和获取数据写在一起的方式
    stu = Stu.objects.get(id=request.GET.get('sid'))
    # stu不是空就进入
    if stu is not None:
        return render(request, 'seleOne.html', {'stu': stu})
    else:
        return HttpResponse("<h1>没有查询到该数据!</h1>")

# 三重查询
def seleStu(request):
    # 获取要查询的元素
    stu = request.GET.get('Tstu')
    try:
        # 如果以id查询出结果的话,就进入else,如果出错了就进入except
        stuId = Stu.objects.get(id=stu)
        print(stuId)
    except:
        try:
            # 如果以sname查询出结果的话,就进入else,如果出错了就进入except
            stuSname = Stu.objects.get(sname=stu)
            print(stuSname)
        except:
            try:
                # 如果以spwd查询出结果的话,就进入else,如果出错了就进入except
                stuSpwd = Stu.objects.get(spwd=stu)
                print(stuSpwd)
            except:
                return HttpResponse("<h1>查找失败,暂无该数据内容!</h1>")
            else:
                return render(request,'seleOne.html',{'stu':stuSpwd})
        else:
            return render(request, 'seleOne.html', {'stu': stuSname})

    else:
        return render(request, 'seleOne.html', {'stu': stuId})

五.在templates编写前端html页面

1.主页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        function delStu(sid){
            flag = confirm("确定要删除编号为:"+sid+"的数据吗?");
            if (flag){
                window.location.href="/stu/delStu/?sid="+sid;
            }
        }

        function seleStu(){
            var ts=document.getElementById("Tstu").value;
            if (ts!=null && ts!==""){
                window.location.href='/stu/seleStu/?Tstu='+ts;
            }

        }
    </script>
</head>
<body>
    <div align="center">
        <input type="text" id="Tstu">
        <input type="button" value="查询" onclick="seleStu()">
    </div> 
    <table border="1" cellspacing="1" cellpadding="1" bgcolor="#f4a460" align="center">
{#        表头#}
        <tr>
            <th>编号</th>
            <th>姓名</th>
            <th>密码</th>
            <th>操作</th>
        </tr>
        {% for stu in stus %}
            <tr>
                <td>{{ stu.id }}</td>
                <td>{{ stu.sname }}</td>
                <td>{{ stu.spwd }}</td>
                <td>
                    <a href="javascript: delStu({{ stu.id }})">删除</a> 
                    <a href="/stu/updStu/?sid={{ stu.id }}">修改</a> 
                    <a href="/stu/seleOne/?sid={{ stu.id }}">详情</a> 
                </td>
            </tr>
        {% endfor %}

    </table>

</body>
</html>

2.修改页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .sbh{
            color: red;
        }
    </style>
</head>
<body>
    <div align="center">
        <form method="post" action="/stu/updStu/">
            {% csrf_token %}
            编号:<input type="text" name="sid" readonly value="{{ stu.id }}"><span class="sbh">编号不可修改!</span>
            姓名:<input type="text" name="sname" value="{{ stu.sname }}">
            密码:<input type="text" name="spwd" value="{{ stu.spwd }}">
            <input type="submit" value="提交修改信息">
        </form>
    </div>
</body>
</html>

3.查询and详情页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .sbh{
            color: red;
        }
    </style>
</head>
<body>
    <div align="center">
        <form method="post" action="/stu/updStu/">
            {% csrf_token %}
            编号:<input type="text" name="sid" readonly value="{{ stu.id }}"><span class="sbh">编号不可修改!</span>
            姓名:<input type="text" name="sname" value="{{ stu.sname }}">
            密码:<input type="text" name="spwd" value="{{ stu.spwd }}">
            <input type="submit" value="提交修改信息">
        </form>
    </div>
</body>
</html>

六.效果图

django 增删改查mysql django实现增删改查_python

七.小结

本章完成了使用Django框架对数据库的增删改查功能的实现,部分代码比较简单,并且可优化空间很大,其中比较难看的是查询功能的实现,做的比较仓促,之后会优化,感兴趣的小伙伴,动手试一下吧!
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!