day11

内容概要

  • celery执行异步任务,延迟任务,定时任务
  • django中使用celery
  • 轮播图接口加缓存
  • 双写一致性
  • 课程前端页面
  • 课程功能表分拆

celery执行异步任务,延迟任务,定时任务

  1. 异步任务

    任务.delay(参数)

  2. 延迟任务

    任务.apply_async(args=[参数], eta=时间对象)

    如果没有修改时区,需要使用utc事件

    from datetime import datetime, timedelta
    
    res1 = datetime.utcnow() + timedelta(seconds=4)
    
    res = add.apply_async(args=[4, 9], eta=res1)
    print(res)
    

    image-20230309180628972

  3. 定时任务

    需要启动beat和启动worker

    beat 定时提交任务的进程---》配置在

    ​ app.conf.beat_schedule任务

    worker 执行任务的

    import os
    
    from celery import Celery
    import sys
    from pathlib import Path
    
    # BASE_DIR = Path(__file__).resolve().parent.parent
    # 提交的异步任务,放在里面
    # os.path.join(BASE_DIR)
    
    broker = 'redis://127.0.0.1:6379/1'
    
    # 执行完的结果,放在这里
    backend = 'redis://127.0.0.1:6379/2'
    
    app = Celery('test', broker=broker, backend=backend)
    
    
    @app.task
    def add(a, b):
        return a + b
    
    
    from celery.schedules import crontab
    from datetime import datetime, timedelta
    
    # 使用步骤
    # 第一步:在app的文件写导
    app.conf.timezone = "Asia/Shanghai"  # 设置时区
    # 是否使用UTC
    app.conf.enable_utc = False
    
    # celery的配置文件
    # 任务的定时配置, 就是配置在那个时间 提交任务的, 提交什么任务
    app.conf.beat_schedule = {
        'add': {
            # 提交这个任务
            "task": 'add',
            # 每三秒提交一次任务,
            'schedule': timedelta(seconds=3),
            # 每周一早八点
            # 'schedule': crontab(hour=8, day_of_week=1),
            # 每个天9点43
            # 'schedule': crontab(hour=9, minute=43),
            'args': (4, 6)
        }
    }
    
    import sys
    print(sys.path)
    

    如果是单例的得写到 app的里面。

django中使用celery

补充:如果在公司中,只是做定时任务,还有一个更简单的框架

APSchedule:

https://blog.csdn.net/qq_41341757/article/details/118759836

使用步骤

-1 把咱们写的包,复制到项目目录下

​ -luffy_api

​ -celery_task celery的包路径

​ -luffy_api 源代码路径

-2 在使用提交异步任务的位置,导入使用即可

​ -视图函数中使用,导入使用

​ -任务.delay() 提交任务

-3 启动worker,如果有定时任务,启动beat

-4 等待任务被 worker执行

-5 在视图函数中,查询任务执行的结果

方式一:

image-20230309195842557

方式二:

起一个名字

image-20230309200219745

image-20230309200237505

直接写这个名字就行了

## 第二步:启动beat
celery -A celery_t1 beat -l info
        
## 第三步:启动worker
celery -A celery_t1 worker -l info -P eventlet

注意点:

  1. 启动命令的执行位置,如果是包结构,一定在包这一层
  2. include=["celery_t1.task1"],路径从包名下开始导入,因为我们在包这层执行的命令

2.1 秒杀功能

秒杀的逻辑

  1. 前端秒杀按钮,用户点击 ---》发送ajax请求到后端
  2. 视图函数--->提前秒杀任务--》借助于celery,提交到中间件中了(celery 提交任务)
  3. 当次秒杀的请求,就回去了,携带者任务id号在前端(异步)
  4. 前端开启定时任务,每隔3s秒钟,带着任务,向后端发送请求,查看是否秒杀成功
  5. 后端情况
    1. 任务还在等待被执行---》返回给前端,前端继续每隔 3s发送一次请求
    2. 任务执行完了,秒杀成功了---》返回给前端,恭喜您秒杀成功---》关闭前端定时器
    3. 任务执行完了,秒杀失败了 --》返回给前端,秒杀失败--》关闭前端定时器

2.2 django中使用celery

前端代码

<template>
  <div>
    <el-button type="success" @click="MySeckill">秒杀</el-button>
  </div>
</template>

<script>
export default {
  name: "Seckill",
  data() {
    return {
      FunID: '',
      t: null
    }
  },
  methods: {
    MySeckill() {
      this.$axios.get(this.$settings.BASE_URL + "/user/seckill/seckill/").then(
          res => {
            if (res.data.code === 100) {
              this.FunID = res.data.id
              if (this.t === null) {
                this.t = setInterval(() => {
                  this.$axios({
                    url: this.$settings.BASE_URL + "/user/seckill/result_fun/",
                    method: "post",
                    data: {"id": this.FunID}
                  }).then(res => {
                    if (res.data.code === 100) {
                      this.$message(res.data.msg)
                      clearInterval(this.t)
                      this.t = 11
                    }
                  })
                }, 3000)
              }
            }
          }
      )
    },
  }
}
</script>

<style scoped>

</style>
  1. 把咱们写的包,复制到姓名目录下

    -luffy_api

    ​ -celery_t1

    ​ -celery.py

    ​ -task.py

    ​ -task1.py

    ​ 后端 view层

    from rest_framework.viewsets import ViewSet
    from celery_t1.task1 import seckill
    from celery.result import AsyncResult
    from celery_t1.celery import app
    
    
    class Seckill(ViewSet):
        @action(methods=["GET"], detail=False)
        def seckill(self, request):
            res = seckill.delay()
            return APIResponse(id=str(res))
    
        @action(methods=["POST"], detail=False)
        def result_fun(self, request):
            a = AsyncResult(id=request.data.get("id"), app=app)
            if a.successful():
                result = a.get()
                if result:
                    return APIResponse(msg="秒杀成功")
                return APIResponse(msg="秒杀失败")
            elif a.status == 'PENDING':
                return APIResponse(code=101, msg="任务等待中被执行")
    

    url层

    route.register("seckill", views.Seckill, 'seckill')
    

    celery的 任务

    # 秒杀任务
    @app.task(name="seckill")
    def seckill():
        time.sleep(random.randint(6, 9))
        return random.choice([True, False])
    

    image-20230309211745152

轮播图接口加缓存

  1. 网站首页被访问的频率很高,瞬间 1w个人在访问,首页的轮播图接口会执行1w次,1w次查询轮播图就会有1w次去走sql,去访问1w MySQL, 这MySQL肯定受不了。可能会挂掉
  2. 想一种方式,让这1w个访问,效率更高一些,不查数据库了,直接走缓存---》redis--》效率高
  3. 现在的逻辑变成了
    1. 轮播图接口请求来了,先去缓存中看,如果有,直接返回
    2. 如果没有,查数据库,然后把轮播图数据,放到redis中,缓存起来
def list(self, request, *args, **kwargs):
    if cache.get("banner_list"):
        res = cache.get("banner_list")
        print("缓存")
    else:
        res = super().list(request, *args, **kwargs).data
        cache.set("banner_list", res)
        print("数据库")
    return APIResponse(data=res)

image-20230309213724282

这种有问题,如果现在修改轮播图的数据,则不会实时显示数据库里面的数据

双写一致性

加入缓存后,缓存中有数据,先去缓存拿,但是如果mysql中数据变了,缓存不会自动变化,出现数据不一致的问题
mysql 和 缓存数据库 数据不一致

解决这个问题有三种方案

第一种:修改数据,删除缓存

第二种:修改数据,更新缓存

第三种: 写一个定时任务,刷新缓存

首页轮播图定时更新

celery,任务层

# 定时任务 更新缓存


#  如果你仅仅想用django的东西就必须写这两条代码
# 想运行得 导入 django   django.setup()
from django.conf import settings
from home.serialiizer.banner_serializer import BannerSerializer
from django.core.cache import cache
from home.models import Banner  # 这个时候 home 还没有注册


@app.task(name='banner_func')
def banner_func():
    """
    获取 全部的 轮播图
    """
    banner_query_set = Banner.objects.filter(is_delete=False, is_show=True).order_by("orders")
    res = BannerSerializer(instance=banner_query_set, many=True)
    for obj in res.data:
        obj['image'] = settings.END_URL + obj['image']
    cache.set("banner_list", res.data)

image-20230309224350075

celery层

from celery import Celery
import os

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'luffy_api.settings.dev')

broker = 'redis://127.0.0.1:6379/1'
backend = 'redis://127.0.0.1:6379/2'

app = Celery(backend=backend, broker=broker,
             include=["celery_t1.task", "celery_t1.task1"])

app.conf.beat_schedule = {
    # 'add': {
    #     'task': 'a1a1',
    #     'schedule': 3,
    # },
    "banner": {
        'task': 'banner_func',
        'schedule': 3,
    },
}

课程前端页面

免费课,实战课,轻课

  • 不要钱的,免费的
  • 实战课,python面向对象 39.9
  • 线下课程完整版的视频 19999

课程列表页数据

前端的路由

import Vue from 'vue'
import VueRouter from 'vue-router'
import HomeView from '../views/HomeView.vue'
import Seckill from "@/components/Seckill";
import ActualCourserView from "@/views/ActualCourserView";
import FreeCourserView from "@/views/FreeCourserView";
import LightCourseView from "@/views/LightCourseView";


Vue.use(VueRouter)

const routes = [
    {
        path: '/',
        name: 'home',
        component: HomeView
    },
    {
        path: '/seckille',
        name: 'seckille',
        component: Seckill
    },
    {
        path: '/actual-course',
        name: 'actual',
        component: ActualCourserView
    },
    {
        path: '/free-course',
        name: 'seckille',
        component: FreeCourserView
    },
    {
        path: '/light-course',
        name: 'seckille',
        component: LightCourseView

    },

]

const router = new VueRouter({
    mode: 'history',
    base: process.env.BASE_URL,
    routes
})

export default router

实战课

<template>
  <div class="course">
    <Header></Header>
    <div class="main">
      <!-- 筛选条件 -->
      <div class="condition">
        <ul class="cate-list">
          <li class="title">课程分类:</li>
          <li class="this">全部</li>
          <li>Python</li>
          <li>Linux运维</li>
          <li>Python进阶</li>
          <li>开发工具</li>
          <li>Go语言</li>
          <li>机器学习</li>
          <li>技术生涯</li>
        </ul>

        <div class="ordering">
          <ul>
            <li class="title">筛&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;选:</li>
            <li class="default this">默认</li>
            <li class="hot">人气</li>
            <li class="price">价格</li>
          </ul>
          <p class="condition-result">共21个课程</p>
        </div>

      </div>
      <!-- 课程列表 -->
      <div class="course-list">
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
      </div>
    </div>
    <Footer></Footer>
  </div>
</template>

<script>
import Header from "@/components/Header"
import Footer from "@/components/Footer"

export default {
  name: "Course",
  data() {
    return {
      category: 0,
    }
  },
  components: {
    Header,
    Footer,
  }
}
</script>

<style scoped>
.course {
  background: #f6f6f6;
}

.course .main {
  width: 1100px;
  margin: 35px auto 0;
}

.course .condition {
  margin-bottom: 35px;
  padding: 25px 30px 25px 20px;
  background: #fff;
  border-radius: 4px;
  box-shadow: 0 2px 4px 0 #f0f0f0;
}

.course .cate-list {
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
  padding-bottom: 18px;
  margin-bottom: 17px;
}

.course .cate-list::after {
  content: "";
  display: block;
  clear: both;
}

.course .cate-list li {
  float: left;
  font-size: 16px;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
  border: 1px solid transparent; /* transparent 透明 */
}

.course .cate-list .title {
  color: #888;
  margin-left: 0;
  letter-spacing: .36px;
  padding: 0;
  line-height: 28px;
}

.course .cate-list .this {
  color: #ffc210;
  border: 1px solid #ffc210 !important;
  border-radius: 30px;
}

.course .ordering::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering ul {
  float: left;
}

.course .ordering ul::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering .condition-result {
  float: right;
  font-size: 14px;
  color: #9b9b9b;
  line-height: 28px;
}

.course .ordering ul li {
  float: left;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
}

.course .ordering .title {
  font-size: 16px;
  color: #888;
  letter-spacing: .36px;
  margin-left: 0;
  padding: 0;
  line-height: 28px;
}

.course .ordering .this {
  color: #ffc210;
}

.course .ordering .price {
  position: relative;
}

.course .ordering .price::before,
.course .ordering .price::after {
  cursor: pointer;
  content: "";
  display: block;
  width: 0px;
  height: 0px;
  border: 5px solid transparent;
  position: absolute;
  right: 0;
}

.course .ordering .price::before {
  border-bottom: 5px solid #aaa;
  margin-bottom: 2px;
  top: 2px;
}

.course .ordering .price::after {
  border-top: 5px solid #aaa;
  bottom: 2px;
}

.course .course-item:hover {
  box-shadow: 4px 6px 16px rgba(0, 0, 0, .5);
}

.course .course-item {
  width: 1100px;
  background: #fff;
  padding: 20px 30px 20px 20px;
  margin-bottom: 35px;
  border-radius: 2px;
  cursor: pointer;
  box-shadow: 2px 3px 16px rgba(0, 0, 0, .1);
  /* css3.0 过渡动画 hover 事件操作 */
  transition: all .2s ease;
}

.course .course-item::after {
  content: "";
  display: block;
  clear: both;
}

/* 顶级元素 父级元素  当前元素{} */
.course .course-item .course-image {
  float: left;
  width: 423px;
  height: 210px;
  margin-right: 30px;
}

.course .course-item .course-image img {
  width: 100%;
}

.course .course-item .course-info {
  float: left;
  width: 596px;
}

.course-item .course-info h3 {
  font-size: 26px;
  color: #333;
  font-weight: normal;
  margin-bottom: 8px;
}

.course-item .course-info h3 span {
  font-size: 14px;
  color: #9b9b9b;
  float: right;
  margin-top: 14px;
}

.course-item .course-info h3 span img {
  width: 11px;
  height: auto;
  margin-right: 7px;
}

.course-item .course-info .teather-info {
  font-size: 14px;
  color: #9b9b9b;
  margin-bottom: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
}

.course-item .course-info .teather-info span {
  float: right;
}

.course-item .lesson-list::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .lesson-list li {
  float: left;
  width: 44%;
  font-size: 14px;
  color: #666;
  padding-left: 22px;
  /* background: url("路径") 是否平铺 x轴位置 y轴位置 */
  background: url("/src/assets/img/play-icon-gray.svg") no-repeat left 4px;
  margin-bottom: 15px;
}

.course-item .lesson-list li .lesson-title {
  /* 以下3句,文本内容过多,会自动隐藏,并显示省略符号 */
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
  display: inline-block;
  max-width: 200px;
}

.course-item .lesson-list li:hover {
  background-image: url("/src/assets/img/play-icon-yellow.svg");
  color: #ffc210;
}

.course-item .lesson-list li .free {
  width: 34px;
  height: 20px;
  color: #fd7b4d;
  vertical-align: super;
  margin-left: 10px;
  border: 1px solid #fd7b4d;
  border-radius: 2px;
  text-align: center;
  font-size: 13px;
  white-space: nowrap;
}

.course-item .lesson-list li:hover .free {
  color: #ffc210;
  border-color: #ffc210;
}

.course-item .pay-box::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .pay-box .discount-type {
  padding: 6px 10px;
  font-size: 16px;
  color: #fff;
  text-align: center;
  margin-right: 8px;
  background: #fa6240;
  border: 1px solid #fa6240;
  border-radius: 10px 0 10px 0;
  float: left;
}

.course-item .pay-box .discount-price {
  font-size: 24px;
  color: #fa6240;
  float: left;
}

.course-item .pay-box .original-price {
  text-decoration: line-through;
  font-size: 14px;
  color: #9b9b9b;
  margin-left: 10px;
  float: left;
  margin-top: 10px;
}

.course-item .pay-box .buy-now {
  width: 120px;
  height: 38px;
  background: transparent;
  color: #fa6240;
  font-size: 16px;
  border: 1px solid #fd7b4d;
  border-radius: 3px;
  transition: all .2s ease-in-out;
  float: right;
  text-align: center;
  line-height: 38px;
}

.course-item .pay-box .buy-now:hover {
  color: #fff;
  background: #ffc210;
  border: 1px solid #ffc210;
}
</style>

免费课

<template>
  <div class="course">
    <Header></Header>
    <div class="main">
      <!-- 筛选条件 -->
      <div class="condition">
        <ul class="cate-list">
          <li class="title">课程分类:</li>
          <li class="this">全部</li>
          <li>Python</li>
          <li>Linux运维</li>
          <li>Python进阶</li>
          <li>开发工具</li>
          <li>Go语言</li>
          <li>机器学习</li>
          <li>技术生涯</li>
        </ul>

        <div class="ordering">
          <ul>
            <li class="title">筛&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;选:</li>
            <li class="default this">默认</li>
            <li class="hot">人气</li>
            <li class="price">价格</li>
          </ul>
          <p class="condition-result">共21个课程</p>
        </div>

      </div>
      <!-- 课程列表 -->
      <div class="course-list">
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
        <div class="course-item">
          <div class="course-image">
            <img src="@/assets/img/course-cover.jpeg" alt="">
          </div>
          <div class="course-info">
            <h3>Python开发21天入门 <span><img src="@/assets/img/avatar1.svg" alt="">100人已加入学习</span></h3>
            <p class="teather-info">Alex 金角大王 老男孩Python教学总监 <span>共154课时/更新完成</span></p>
            <ul class="lesson-list">
              <li><span class="lesson-title">01 | 第1节:初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span> <span class="free">免费</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码</span></li>
              <li><span class="lesson-title">01 | 第1节:初识编码初识编码</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">限时免费</span>
              <span class="discount-price">¥0.00元</span>
              <span class="original-price">原价:9.00元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>
      </div>
    </div>
    <Footer></Footer>
  </div>
</template>

<script>
import Header from "@/components/Header"
import Footer from "@/components/Footer"

export default {
  name: "Course",
  data() {
    return {
      category: 0,
    }
  },
  components: {
    Header,
    Footer,
  }
}
</script>

<style scoped>
.course {
  background: #f6f6f6;
}

.course .main {
  width: 1100px;
  margin: 35px auto 0;
}

.course .condition {
  margin-bottom: 35px;
  padding: 25px 30px 25px 20px;
  background: #fff;
  border-radius: 4px;
  box-shadow: 0 2px 4px 0 #f0f0f0;
}

.course .cate-list {
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
  padding-bottom: 18px;
  margin-bottom: 17px;
}

.course .cate-list::after {
  content: "";
  display: block;
  clear: both;
}

.course .cate-list li {
  float: left;
  font-size: 16px;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
  border: 1px solid transparent; /* transparent 透明 */
}

.course .cate-list .title {
  color: #888;
  margin-left: 0;
  letter-spacing: .36px;
  padding: 0;
  line-height: 28px;
}

.course .cate-list .this {
  color: #ffc210;
  border: 1px solid #ffc210 !important;
  border-radius: 30px;
}

.course .ordering::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering ul {
  float: left;
}

.course .ordering ul::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering .condition-result {
  float: right;
  font-size: 14px;
  color: #9b9b9b;
  line-height: 28px;
}

.course .ordering ul li {
  float: left;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
}

.course .ordering .title {
  font-size: 16px;
  color: #888;
  letter-spacing: .36px;
  margin-left: 0;
  padding: 0;
  line-height: 28px;
}

.course .ordering .this {
  color: #ffc210;
}

.course .ordering .price {
  position: relative;
}

.course .ordering .price::before,
.course .ordering .price::after {
  cursor: pointer;
  content: "";
  display: block;
  width: 0px;
  height: 0px;
  border: 5px solid transparent;
  position: absolute;
  right: 0;
}

.course .ordering .price::before {
  border-bottom: 5px solid #aaa;
  margin-bottom: 2px;
  top: 2px;
}

.course .ordering .price::after {
  border-top: 5px solid #aaa;
  bottom: 2px;
}

.course .course-item:hover {
  box-shadow: 4px 6px 16px rgba(0, 0, 0, .5);
}

.course .course-item {
  width: 1100px;
  background: #fff;
  padding: 20px 30px 20px 20px;
  margin-bottom: 35px;
  border-radius: 2px;
  cursor: pointer;
  box-shadow: 2px 3px 16px rgba(0, 0, 0, .1);
  /* css3.0 过渡动画 hover 事件操作 */
  transition: all .2s ease;
}

.course .course-item::after {
  content: "";
  display: block;
  clear: both;
}

/* 顶级元素 父级元素  当前元素{} */
.course .course-item .course-image {
  float: left;
  width: 423px;
  height: 210px;
  margin-right: 30px;
}

.course .course-item .course-image img {
  width: 100%;
}

.course .course-item .course-info {
  float: left;
  width: 596px;
}

.course-item .course-info h3 {
  font-size: 26px;
  color: #333;
  font-weight: normal;
  margin-bottom: 8px;
}

.course-item .course-info h3 span {
  font-size: 14px;
  color: #9b9b9b;
  float: right;
  margin-top: 14px;
}

.course-item .course-info h3 span img {
  width: 11px;
  height: auto;
  margin-right: 7px;
}

.course-item .course-info .teather-info {
  font-size: 14px;
  color: #9b9b9b;
  margin-bottom: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
}

.course-item .course-info .teather-info span {
  float: right;
}

.course-item .lesson-list::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .lesson-list li {
  float: left;
  width: 44%;
  font-size: 14px;
  color: #666;
  padding-left: 22px;
  /* background: url("路径") 是否平铺 x轴位置 y轴位置 */
  background: url("/src/assets/img/play-icon-gray.svg") no-repeat left 4px;
  margin-bottom: 15px;
}

.course-item .lesson-list li .lesson-title {
  /* 以下3句,文本内容过多,会自动隐藏,并显示省略符号 */
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
  display: inline-block;
  max-width: 200px;
}

.course-item .lesson-list li:hover {
  background-image: url("/src/assets/img/play-icon-yellow.svg");
  color: #ffc210;
}

.course-item .lesson-list li .free {
  width: 34px;
  height: 20px;
  color: #fd7b4d;
  vertical-align: super;
  margin-left: 10px;
  border: 1px solid #fd7b4d;
  border-radius: 2px;
  text-align: center;
  font-size: 13px;
  white-space: nowrap;
}

.course-item .lesson-list li:hover .free {
  color: #ffc210;
  border-color: #ffc210;
}

.course-item .pay-box::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .pay-box .discount-type {
  padding: 6px 10px;
  font-size: 16px;
  color: #fff;
  text-align: center;
  margin-right: 8px;
  background: #fa6240;
  border: 1px solid #fa6240;
  border-radius: 10px 0 10px 0;
  float: left;
}

.course-item .pay-box .discount-price {
  font-size: 24px;
  color: #fa6240;
  float: left;
}

.course-item .pay-box .original-price {
  text-decoration: line-through;
  font-size: 14px;
  color: #9b9b9b;
  margin-left: 10px;
  float: left;
  margin-top: 10px;
}

.course-item .pay-box .buy-now {
  width: 120px;
  height: 38px;
  background: transparent;
  color: #fa6240;
  font-size: 16px;
  border: 1px solid #fd7b4d;
  border-radius: 3px;
  transition: all .2s ease-in-out;
  float: right;
  text-align: center;
  line-height: 38px;
}

.course-item .pay-box .buy-now:hover {
  color: #fff;
  background: #ffc210;
  border: 1px solid #ffc210;
}
</style>

轻客

<template>
  <div>
    <Header></Header>
    <div>
      <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
    </div>
    <Footer></Footer>
  </div>
</template>

<script>
import Header from "@/components/Header"
import Footer from "@/components/Footer";


export default {
  name: "LightCourseView",
  components: {
    Header,
    Footer,
  }
}
</script>

<style scoped>

</style>

课程功能表分析

轻课,实战课,免费课, 需要几个表

所有课程使用一个表,通过类型区分,但是坑你出现字段不一样,数据量越来越来,导致表查询速度慢

  • 一种课程一个表

实战课程线---》分析出5张表

  • 课程分类表 一个分类下有多个课程跟课程一对多
  • 实战课表 一个实战课,会有多个章节,跟章节一对多
  • 章节表 一个章节下有多个课时,章节和课时一对多
  • 课时表
  • 老师表 跟实战课一对多

​ -正常课程 有评论,需要建立评论表,评论板块没写,这个表就不写了

from django.db import models
from utils.common_model import BaseModel


# Create your models here.
# 5张:课程分类,实战课,章节,课时,老师表


# 课程分类表
class CourseCategory(BaseModel):
    """分类"""
    name = models.CharField(max_length=64, unique=True, verbose_name="分类名称")

    class Meta:
        db_table = "luffy_course_category"
        verbose_name = "分类"
        verbose_name_plural = verbose_name

    def __str__(self):
        return "%s" % self.name


# 实战课表
class Course(BaseModel):
    """课程"""
    course_type = (
        (0, '付费'),
        (1, 'VIP专享'),
        (2, '学位课程')
    )
    level_choices = (
        (0, '初级'),
        (1, '中级'),
        (2, '高级'),
    )
    status_choices = (
        (0, '上线'),
        (1, '下线'),
        (2, '预上线'),
    )
    name = models.CharField(max_length=128, verbose_name="课程名称")
    course_img = models.ImageField(upload_to="courses", max_length=255, verbose_name="封面图片", blank=True, null=True)
    course_type = models.SmallIntegerField(choices=course_type, default=0, verbose_name="付费类型")
    brief = models.TextField(max_length=2048, verbose_name="详情介绍", null=True, blank=True)
    level = models.SmallIntegerField(choices=level_choices, default=0, verbose_name="难度等级")
    pub_date = models.DateField(verbose_name="发布日期", auto_now_add=True)
    period = models.IntegerField(verbose_name="建议学习周期(day)", default=7)
    attachment_path = models.FileField(upload_to="attachment", max_length=128, verbose_name="课件路径", blank=True,null=True)
    status = models.SmallIntegerField(choices=status_choices, default=0, verbose_name="课程状态")

    students = models.IntegerField(verbose_name="学习人数", default=0) # 跟用户表做关联,优化字段

    sections = models.IntegerField(verbose_name="总课时数量", default=0)
    pub_sections = models.IntegerField(verbose_name="课时更新数量", default=0)
    price = models.DecimalField(max_digits=6, decimal_places=2, verbose_name="课程原价", default=0)

    # on_delete 级联删除,出了级联删除外,还有 很多其他的,暂时先不讲
    teacher = models.ForeignKey("Teacher", on_delete=models.DO_NOTHING, null=True, blank=True, verbose_name="授课老师")
    course_category = models.ForeignKey("CourseCategory", on_delete=models.SET_NULL, db_constraint=False, null=True,blank=True, verbose_name="课程分类")
    class Meta:
        db_table = "luffy_course"
        verbose_name = "课程"
        verbose_name_plural = "课程"

    def __str__(self):
        return "%s" % self.name


# 章节表
class CourseChapter(BaseModel):
    """章节"""
    # 章节跟课程一对多,关联字段写在多的一方
    # related_name 暂时先不讲
    course = models.ForeignKey("Course", related_name='coursechapters', on_delete=models.CASCADE, verbose_name="课程名称")
    chapter = models.SmallIntegerField(verbose_name="第几章", default=1)
    name = models.CharField(max_length=128, verbose_name="章节标题")
    summary = models.TextField(verbose_name="章节介绍", blank=True, null=True)
    pub_date = models.DateField(verbose_name="发布日期", auto_now_add=True)

    class Meta:
        db_table = "luffy_course_chapter"
        verbose_name = "章节"
        verbose_name_plural = verbose_name

    def __str__(self):
        return "%s:(第%s章)%s" % (self.course, self.chapter, self.name)


# 课时表
class CourseSection(BaseModel):
    """课时"""
    section_type_choices = (
        (0, '文档'),
        (1, '练习'),
        (2, '视频')
    )
    # 课时跟章节一对多,关联写段写在多的一方
    chapter = models.ForeignKey("CourseChapter", related_name='coursesections', on_delete=models.CASCADE,verbose_name="课程章节")
    name = models.CharField(max_length=128, verbose_name="课时标题")
    orders = models.PositiveSmallIntegerField(verbose_name="课时排序")
    section_type = models.SmallIntegerField(default=2, choices=section_type_choices, verbose_name="课时种类")
    section_link = models.CharField(max_length=255, blank=True, null=True, verbose_name="课时链接",help_text="若是video,填vid,若是文档,填link")
    duration = models.CharField(verbose_name="视频时长", blank=True, null=True, max_length=32)  # 仅在前端展示使用
    pub_date = models.DateTimeField(verbose_name="发布时间", auto_now_add=True)
    free_trail = models.BooleanField(verbose_name="是否可试看", default=False)

    class Meta:
        db_table = "luffy_course_section"
        verbose_name = "课时"
        verbose_name_plural = verbose_name

    def __str__(self):
        return "%s-%s" % (self.chapter, self.name)


# 老师表
class Teacher(BaseModel):
    """导师"""
    role_choices = (
        (0, '讲师'),
        (1, '导师'),
        (2, '班主任'),
    )
    name = models.CharField(max_length=32, verbose_name="导师名")
    role = models.SmallIntegerField(choices=role_choices, default=0, verbose_name="导师身份")
    title = models.CharField(max_length=64, verbose_name="职位、职称")
    signature = models.CharField(max_length=255, verbose_name="导师签名", help_text="导师签名", blank=True, null=True)
    image = models.ImageField(upload_to="teacher", null=True, verbose_name="导师封面")
    brief = models.TextField(max_length=1024, verbose_name="导师描述")

    class Meta:
        db_table = "luffy_teacher"
        verbose_name = "导师"
        verbose_name_plural = verbose_name

    def __str__(self):
        return "%s" % self.name

    
    
    
    # 执行迁移命令
posted @ 2023-03-09 23:28  可否  阅读(58)  评论(0)    收藏  举报