celery包结构
project
├── celery_task # celery包
│ ├── __init__.py # 包文件
│ ├── celery.py # celery连接和配置相关文件，且名字必须叫celery.py
│ └── tasks.py # 所有任务函数
├── add_task.py # 添加任务
└── get_result.py # 获取结果
### 1 创建 celery_task 包，包内部有celery.py和一堆task-->['celery_task.home_task','celery_task.user_task']
### 2 celery.py
from celery import Celery
broker = 'redis://127.0.0.1:6379/1' # 消息中间件 redis
backend = 'redis://127.0.0.1:6379/2' # 结果存，用redis
app = Celery('app', broker=broker, backend=backend,include=['celery_task.home_task','celery_task.user_task'])
###3 每个task，写自己相关的任务
### 4 启动worker
celery -A celery_task worker -l info -P eventlet
### 5 提交任务
from celery_task.home_task import add
res=add.delay(3,4)
print(res)
### 6 查看结果
from celery_task.celery import app
from celery.result import AsyncResult
id = 'e31441d9-e9a6-4d70-9a66-a9227a6bc273'
if __name__ == '__main__':
a = AsyncResult(id=id, app=app)
if a.successful():
result = a.get()
print(result)
elif a.failed():
print('任务失败')
elif a.status == 'PENDING':
print('任务等待中被执行')
elif a.status == 'RETRY':
print('任务异常后正在重试')
elif a.status == 'STARTED':
print('任务已经开始被执行')
celery延迟任务和定时任务
异步任务
### 提交任务,使用delay提交即可
from celery_task.home_task import add
res=add.delay(3,4)
print(res)
延时任务
## 提交延迟任务 apply_async
# 添加延迟任务
from datetime import datetime, timedelta
print(datetime.utcnow()) # utc 时间，跟咱们差8个小时
# eta 就是 10s 后的实际
eta = datetime.utcnow() + timedelta(seconds=30)
res = send_sms.apply_async(args=(18953675221,), eta=eta)
print(res)
定时任务
#### 1 在celery.py中
# 时区
app.conf.timezone = 'Asia/Shanghai'
# 是否使用UTC
app.conf.enable_utc = False
# 任务的定时配置
from datetime import timedelta
from celery.schedules import crontab
app.conf.beat_schedule = {
'add': {
'task': 'celery_task.home_task.add',
'schedule': timedelta(seconds=3),
# 'schedule': crontab(hour=8, day_of_week=1), # 每周一早八点
'args': (5, 6),
},
'send_sms': {
'task': 'celery_task.user_task.send_sms',
# 'schedule': crontab(hour=8, day_of_week=1), # 每周一早八点
'schedule': crontab(hour=9, minute=39), # 每天9点39，执行
'args': (18923748221,),
},
}
###2 启动worker
celery -A celery_task worker -l info -P eventlet
### 3 启动beat(它来定时提交任务)
celery -A celery_task beat -l info
django中使用celery
# 通用方案
#1 把咱们之前写的包，放到项目路径下
#2 提交异步或延迟任务，导入直接提交即可
from celery_task.user_task import cache_demo
res = cache_demo.delay('phone','1872324242')
# 3 只要启动worker，这些任务就会被执行
# 4 如果要使用django中的东西（配置文件，缓存，orm。。。），都需要在celery.py中写
import os
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'luffy_api.settings.dev')
#5 使用django内置东西的任务
@app.task
def cache_demo(key, value):
cache.set(key, value)
return '缓存成功'
接口缓存
# 1 首页获取轮播图接口---》去数据库查的---》每次来到首页，都要查一次----》轮播图变得很慢
# 2 咱们把轮播图数据，放到redis，做缓存
-以后：只要缓存中有，就从缓存中拿(redis)
-如果缓存中没有，从数据库查，查完再放到缓存中
# 3 查询所有的接口，都可以加缓存
轮播图接口加缓存
class BannerView(GenericViewSet, ListModelMixin): # 自动生成路由
queryset = Banner.objects.filter(is_delete=False, is_show=True).order_by('orders')[:settings.BANNER_COUNT]
serializer_class = BannerSerializer
# 接口加缓存，重写list
def list(self, request, *args, **kwargs):
# 先去缓存中查，如果有，直接返回
banner_list = cache.get('banner_list')
if not banner_list:
# 如果没有，在查数据库，放到缓存，再返回
logger.info('走了数据库')
res = super().list(request, *args, **kwargs)
cache.set('banner_list', res.data)
return APIResponse(result=res.data)
logger.info('走了缓存')
return APIResponse(result=banner_list)
缓存升级（类，装饰器）
from django.core.cache import cache
from utils.common_logger import logger
class CacheListModelMixin(ListModelMixin):
# 接口加缓存，重写list
def list(self, request, *args, **kwargs):
# 先去缓存中查，如果有，直接返回
data_list = cache.get(self.cache_key)
if not data_list:
# 如果没有，在查数据库，放到缓存，再返回
logger.info('走了数据库')
res = super().list(request, *args, **kwargs)
cache.set(self.cache_key, res.data)
return APIResponse(result=res.data)
logger.info('走了缓存')
return APIResponse(result=data_list)
### 视图类
class BannerView(GenericViewSet, CacheListModelMixin): # 自动生成路由
queryset = Banner.objects.filter(is_delete=False, is_show=True).order_by('orders')[:settings.BANNER_COUNT]
serializer_class = BannerSerializer
cache_key = 'banner_list'
双写一致性
# 1 接口加缓存----》mysql数据改了---》缓存数据没动---》数据不一致了
- 有的数据，必须一致（缓存删除和修改，要在修改数据后）
-修改，插入数据（mysql），删除缓存
-修改，插入数据（mysql），修改缓存
----不合理的方案----
删除缓存，再改数据
- 有的数据，可以容忍--->实时性要求没有那么高
-定时更新 ---》每隔5分钟更新一次
# 2 高级名： 双写一致性
当修改了数据库中的数据同时也需要修改缓存中的数据,如何保证数据库中和缓存中的数据一致,这就是双写一致性
解决方案：
-改数据，删除缓存，该缓存
-定时更新
# celery:发送短信，改成异步
# celery：定时更新轮播图缓存
django缓存过期时间
cache.set(self.cache_key, res.data, None) # 永不过期
cache.set(self.cache_key, res.data) # 不写5分钟过期
通过定时更新缓存，实现双写一致性
#####1 任务
@app.task
def update_banner():
# 1 查出所有轮播图
banner_list = Banner.objects.filter(is_delete=False, is_show=True).order_by('orders')[:settings.BANNER_COUNT]
ser = BannerSerializer(instance=banner_list, many=True)
for item in ser.data:
item['image']=settings.BACKEND_URL+item['image']
# 2 把轮播图放到cache中
cache.set('banner_list', ser.data)
return '更新成功'
### 2 celery.py
app.conf.beat_schedule = {
'update_banner': {
'task': 'celery_task.home_task.update_banner',
'schedule': timedelta(minutes=2),
'args': (),
},
}
### 3 启动worker
celery -A celery_task worker -l info -P eventlet
## 4 启动beat
celery -A celery_task beat -l info
异步秒杀逻辑
# 1 分析流程---》提高了 并发量
同步流程：用户在前端，点击秒杀按钮----》提交请求到后端----》[扣减库存，生成订单]假设耗时---》同步操作--》10s钟处理完成，秒杀成功---》返回给前端---》如果秒杀人数过多，同步操作，不能承载更多人同时秒杀
异步流程：用户在前端，点击秒杀按钮----》提交请求到后端----》提交一个任务[扣减库存，生成订单]假设耗时---》异步操作--》10s钟处理完成，秒杀成功---》前端再发请求查询---》如果秒杀人数过多，异步操作，10s内能承载非常多用户操作
前端
const routes = [
{
path: '/',
name: 'home',
component: HomeView
},
{
path: '/seckill',
name: 'seckill',
component: SeckillView
},
]
<template>
<div class="home">
<Header></Header>
<div style="padding: 50px;margin-left: 100px">
<h1>Go语言课程</h1>
<img src="http://photo.liuqingzheng.top/2023%2002%2022%2021%2057%2011%20/image-20230222215707795.png"
height="300px"
width="300px">
<br>
<el-button type="danger" @click="handleSeckill">秒杀课程</el-button>
</div>
<br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
<Footer></Footer>
</div>
</template>
<script>
import Header from "@/components/Header.vue";
import Footer from "@/components/Footer.vue";
export default {
name: "SeckillView",
data() {
return {
seckill_id: '',
t: ''
}
},
methods: {
handleSeckill() {
this.$axios.post(this.$settings.BASE_URL + 'home/seckill/seckill/', {
course_id: 'go语言'
}).then(res => {
console.log(res.data)
if (res.data.code == 100) {
this.$message({
message: res.data.msg,
type: 'warning',
duration: 1500
});
// 起一个定时任务，每隔2s向后端查询一次，看是否秒杀成功
this.seckill_id = res.data.seckill_id
this.t = setInterval(() => {
this.$axios.get(this.$settings.BASE_URL + 'home/seckill/get_seckill_result/?seckill_id='+this.seckill_id).then(res => {
if (res.data.code == 100 || res.data.code == 101) {
alert(res.data.msg)
clearInterval(this.t)
this.t = null
} else if (res.data.code == 102) { //秒杀逻辑还没开始执行
this.$message('等待开始秒杀');
} else if (res.data.code == 103) {
this.$message('正在秒杀途中');
}
})
}, 2000)
} else {
this.$message({
message: '服务端异常，请联系系统管理员',
type: 'warning',
duration: 1500
});
}
})
}
},
components: {
Header, Footer
}
}
</script>
<style scoped>
</style>
后端
from celery_task.home_task import seckill_course
from rest_framework.decorators import action
from celery_task.celery import app
from celery.result import AsyncResult
class SeckillView(GenericViewSet):
@action(methods=['POST'], detail=False)
def seckill(self, request, *args, **kwargs):
# 1 取出课程id resquest.data.get('course_id')，取出当前用户 request.user.pk
course_id = request.data.get('course_id')
# 2 扣减库存---》数据库 --》课程id的课程 数量减一
# 3 订单表，生成一条记录
res = seckill_course.delay(course_id)
# 4 返回给前端，秒杀成功
return APIResponse(seckill_id=str(res), msg='秒杀任务已经提交')
@action(methods=['GET'], detail=False)
def get_seckill_result(self, request, *args, **kwargs):
seckill_id = request.query_params.get('seckill_id')
a = AsyncResult(id=seckill_id, app=app)
if a.successful():
result = a.get()
if result:
return APIResponse(msg='恭喜您，秒杀成功')
else:
return APIResponse(code=101, msg='很遗憾，您没有秒到')
elif a.status == 'PENDING':
print('任务等待中被执行')
return APIResponse(code=102, msg='暂未轮到您')
elif a.status == 'STARTED':
print('任务已经开始被执行')
return APIResponse(code=103, msg='正在秒杀，请稍后')
else:
return APIResponse(code=104, msg='服务端错误，秒杀失败')
路由
router.register('seckill', SeckillView, 'banner')
任务
@app.task
def seckill_course(course_id):
# 2 扣减库存---》数据库 --》课程id的课程 数量减一
# 3 订单表，生成一条记录
# 逻辑是：开启事务---》扣减库存---》生成订单
import time
import random
time.sleep(6)
res = random.choice([100, 102])
if res == 100:
print('%s被秒杀成功了' % course_id)
return True
else:
print('%s被秒杀失败了' % course_id)
return False
课程列表页前端
#1 前端 新建三个组件
LightCourse.vue
FreeCourse.vue
ActualCourse.vue
# 2 配置路由
import FreeCourse from "@/views/FreeCourse";
import ActualCourse from "@/views/ActualCourse";
import LightCourse from "@/views/LightCourse";
{
path: '/free-course',
name: 'free-course',
component: FreeCourse
},
{
path: '/actual-course',
name: 'actual-course',
component: ActualCourse
},
{
path: '/light-course',
name: 'light-course',
component: LightCourse
},
ActualCourse
<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 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>
课程相关表
#1 课程分类表：跟课程一对多：一个课程分类，有多个课程
#2 课程表（实战课课表）
-多种课程：免费，实战，轻课---》使用同一个表？使用三个表
-多种课程，字段可能有一样的，也有不一样的
-我们的设计是：多个课程，多个表，以后再加别的课程，再加表即可
# 3 章节表：一个课程，有多个章节
# 4 课时表：一个章节，有多个课时
# 5 老师表：实战课，一门课，就是一个老师讲， 一对多，一个老师可以讲多门课
# 创建表
from django.db import models
from utils.common_model import BaseModel
# Create your models here.
## 课程分类
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
### 课程表
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)
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)
# 删除某个课程分类，如果使用models.CASCADE，所有课程都删除，很危险
# 删除某个课程分类models.SET_NULL，跟它相关联的课程，置为空
# db_constraint=False 逻辑外键，不建立物理外键 没有外键约束
course_category = models.ForeignKey("CourseCategory", on_delete=models.SET_NULL, db_constraint=False, null=True, blank=True,verbose_name="课程分类")
teacher = models.ForeignKey("Teacher", on_delete=models.DO_NOTHING, null=True, blank=True, verbose_name="授课老师")
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"""
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')
)
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
补充
#1 ForeignKey 的on_delete 参数
'''on_delete 可以选择的参数
models.CASCADE # 级联删除，注意使用时机，用户和用户详情 课程和课程章节
models.SET_NULL # 删除分类，课程这个字段设置为空，要有null=True参数的配合
models.SET_DEFAULT # 删除分类，课程这个字段设置为默认值，要有 defalut=xx参数的配合
models.DO_NOTHING # 删除分类，课程这个字段什么都不做
models.SET(值,函数内存地址) # 删除分类，课程这个字段设置为写的值，或者执行内部传入的函数，函数返回值放在这
'''
# 2 ForeignKey 的db_constraint=False
如果 db_constraint=False 只逻辑外键，不建立物理外键 没有外键约束,如果这样设置，修改，新增速度快，可能会出现脏数据（程序层面控制）
连表查询没有任何区别，其他操作完全一致
# 3 ForeignKey 的 related_name='coursechapters'
# 基于对象的跨表查：
正向： 对象.字段 course.course_category 根据课程拿到了课程分类对象， course_category在表内部，就是正向
反向： 对象.表名小写 对象.表名小写_set.all() 字段在表中没有，但是有关联关系
related_name：
为了替换原来基于对象的跨表查反向查询 表名小写 或 表名小写_set.all() 的
related_query_name
为了替换原来__连表查询，中表名小写，现在直接用related_query_name指定的字符串即可
课程表数据录入
mysql数据查询导入
把media文件夹复制到项目中
INSERT INTO luffy_teacher(id, orders, is_show, is_delete, created_time, updated_time, name, role, title, signature, image, brief) VALUES (1, 1, 1, 0, '2022-07-14 13:44:19.661327', '2022-07-14 13:46:54.246271', 'Alex', 1, '老男孩Python教学总监', '金角大王', 'teacher/alex_icon.png', '老男孩教育CTO & CO-FOUNDER 国内知名PYTHON语言推广者 51CTO学院2016\2017年度最受学员喜爱10大讲师之一 多款开源软件作者 曾任职公安部、飞信、中金公司、NOKIA中国研究院、华尔街英语、ADVENT、汽车之家等公司');
INSERT INTO luffy_teacher(id, orders, is_show, is_delete, created_time, updated_time, name, role, title, signature, image, brief) VALUES (2, 2, 1, 0, '2022-07-14 13:45:25.092902', '2022-07-14 13:45:25.092936', 'Mjj', 0, '前美团前端项目组架构师', NULL, 'teacher/mjj_icon.png', '是马JJ老师, 一个集美貌与才华于一身的男人，搞过几年IOS，又转了前端开发几年，曾就职于美团网任高级前端开发，后来因为不同意王兴(美团老板)的战略布局而出家做老师去了，有丰富的教学经验，开起车来也毫不含糊。一直专注在前端的前沿技术领域。同时，爱好抽烟、喝酒、烫头(锡纸烫)。 我的最爱是前端，因为前端妹子多。');
INSERT INTO luffy_teacher(id, orders, is_show, is_delete, created_time, updated_time, name, role, title, signature, image, brief) VALUES (3, 3, 1, 0, '2022-07-14 13:46:21.997846', '2022-07-14 13:46:21.997880', 'Lyy', 0, '老男孩Linux学科带头人', NULL, 'teacher/lyy_icon.png', 'Linux运维技术专家，老男孩Linux金牌讲师，讲课风趣幽默、深入浅出、声音洪亮到爆炸');
-- 分类表
INSERT INTO luffy_course_category(id, orders, is_show, is_delete, created_time, updated_time, name) VALUES (1, 1, 1, 0, '2022-07-14 13:40:58.690413', '2022-07-14 13:40:58.690477', 'Python');
INSERT INTO luffy_course_category(id, orders, is_show, is_delete, created_time, updated_time, name) VALUES (2, 2, 1, 0, '2022-07-14 13:41:08.249735', '2022-07-14 13:41:08.249817', 'Linux');
-- 课程表
INSERT INTO luffy_course(id, orders, is_show, is_delete, created_time, updated_time, name, course_img, course_type, brief, level, pub_date, period, attachment_path, status, students, sections, pub_sections, price, course_category_id, teacher_id) VALUES (1, 1, 1, 0, '2022-07-14 13:54:33.095201', '2022-07-14 13:54:33.095238', 'Python开发21天入门', 'courses/alex_python.png', 0, 'Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土&&&Python从入门到入土', 0, '2022-07-14', 21, '', 0, 231, 120, 120, 0.00, 1, 1);
INSERT INTO luffy_course(id, orders, is_show, is_delete, created_time, updated_time, name, course_img, course_type, brief, level, pub_date, period, attachment_path, status, students, sections, pub_sections, price, course_category_id, teacher_id) VALUES (2, 2, 1, 0, '2022-07-14 13:56:05.051103', '2022-07-14 13:56:05.051142', 'Python项目实战', 'courses/mjj_python.png', 0, '', 1, '2022-07-14', 30, '', 0, 340, 120, 120, 99.00, 1, 2);
INSERT INTO luffy_course(id, orders, is_show, is_delete, created_time, updated_time, name, course_img, course_type, brief, level, pub_date, period, attachment_path, status, students, sections, pub_sections, price, course_category_id, teacher_id) VALUES (3, 3, 1, 0, '2022-07-14 13:57:21.190053', '2022-07-14 13:57:21.190095', 'Linux系统基础5周入门精讲', 'courses/lyy_linux.png', 0, '', 0, '2022-07-14', 25, '', 0, 219, 100, 100, 39.00, 2, 3);
-- 章节表
INSERT INTO luffy_course_chapter(id, orders, is_show, is_delete, created_time, updated_time, chapter, name, summary, pub_date, course_id) VALUES (1, 1, 1, 0, '2022-07-14 13:58:34.867005', '2022-07-14 14:00:58.276541', 1, '计算机原理', '', '2022-07-14', 1);
INSERT INTO luffy_course_chapter(id, orders, is_show, is_delete, created_time, updated_time, chapter, name, summary, pub_date, course_id) VALUES (2, 2, 1, 0, '2022-07-14 13:58:48.051543', '2022-07-14 14:01:22.024206', 2, '环境搭建', '', '2022-07-14', 1);
INSERT INTO luffy_course_chapter(id, orders, is_show, is_delete, created_time, updated_time, chapter, name, summary, pub_date, course_id) VALUES (3, 3, 1, 0, '2022-07-14 13:59:09.878183', '2022-07-14 14:01:40.048608', 1, '项目创建', '', '2022-07-14', 2);
INSERT INTO luffy_course_chapter(id, orders, is_show, is_delete, created_time, updated_time, chapter, name, summary, pub_date, course_id) VALUES (4, 4, 1, 0, '2022-07-14 13:59:37.448626', '2022-07-14 14:01:58.709652', 1, 'Linux环境创建', '', '2022-07-14', 3);
-- 课时表
INSERT INTO luffy_course_Section(id, is_show, is_delete, created_time, updated_time, name, orders, section_type, section_link, duration, pub_date, free_trail, chapter_id) VALUES (1, 1, 0, '2022-07-14 14:02:33.779098', '2022-07-14 14:02:33.779135', '计算机原理上', 1, 2, NULL, NULL, '2022-07-14 14:02:33.779193', 1, 1);
INSERT INTO luffy_course_Section(id, is_show, is_delete, created_time, updated_time, name, orders, section_type, section_link, duration, pub_date, free_trail, chapter_id) VALUES (2, 1, 0, '2022-07-14 14:02:56.657134', '2022-07-14 14:02:56.657173', '计算机原理下', 2, 2, NULL, NULL, '2022-07-14 14:02:56.657227', 1, 1);
INSERT INTO luffy_course_Section(id, is_show, is_delete, created_time, updated_time, name, orders, section_type, section_link, duration, pub_date, free_trail, chapter_id) VALUES (3, 1, 0, '2022-07-14 14:03:20.493324', '2022-07-14 14:03:52.329394', '环境搭建上', 1, 2, NULL, NULL, '2022-07-14 14:03:20.493420', 0, 2);
INSERT INTO luffy_course_Section(id, is_show, is_delete, created_time, updated_time, name, orders, section_type, section_link, duration, pub_date, free_trail, chapter_id) VALUES (4, 1, 0, '2022-07-14 14:03:36.472742', '2022-07-14 14:03:36.472779', '环境搭建下', 2, 2, NULL, NULL, '2022-07-14 14:03:36.472831', 0, 2);
INSERT INTO luffy_course_Section(id, is_show, is_delete, created_time, updated_time, name, orders, section_type, section_link, duration, pub_date, free_trail, chapter_id) VALUES (5, 1, 0, '2022-07-14 14:04:19.338153', '2022-07-14 14:04:19.338192', 'web项目的创建', 1, 2, NULL, NULL, '2022-07-14 14:04:19.338252', 1, 3);
INSERT INTO luffy_course_Section(id, is_show, is_delete, created_time, updated_time, name, orders, section_type, section_link, duration, pub_date, free_trail, chapter_id) VALUES (6, 1, 0, '2022-07-14 14:04:52.895855', '2022-07-14 14:04:52.895890', 'Linux的环境搭建', 1, 2, NULL, NULL, '2022-07-14 14:04:52.895942', 1, 4);
课程列表页接口
# 1 课程分类接口
# 2 查询所有课程
-1 可以按人气（学生人数）和价格排序
-2 可以按课程分类过滤
-3 带分页（基本分页）
查询所有分类接口
#### 路由
router.register('category', CourseCategoryView, 'category')
### 视图类
class CourseCategoryView(GenericViewSet, CommonListModelMixin):
queryset = CourseCategory.objects.filter(is_delete=False, is_show=True).order_by('orders')
serializer_class = CourseCategorySerializer
### 序列化类
class CourseCategorySerializer(serializers.ModelSerializer):
class Meta:
model = CourseCategory
fields = ['id', 'name']
查询所有课程接口
路由
# http://127.0.0.1:8000/api/v1/courses/actual/--- get
router.register('actual', CourseView, 'actual')
视图类
class CourseView(GenericViewSet, CommonListModelMixin):
queryset = Course.objects.filter(is_delete=False, is_show=True).order_by('orders')
serializer_class = CourseSerializer
filter_backends = [OrderingFilter, DjangoFilterBackend]
ordering_fields = ['students', 'price']
filterset_fields = ['course_category']
# 分页
pagination_class = CommonPageNumberPagination
序列化类
class TeacherSerializer(serializers.ModelSerializer):
class Meta:
model = Teacher
fields = ['id', 'name', 'role_name', 'title', 'signature', 'image', 'brief']
class CourseSerializer(serializers.ModelSerializer):
class Meta:
model = Course
fields = [
'id',
'name',
'course_img',
'brief',
'attachment_path',
'pub_sections',
'price',
'students',
'period',
'sections',
'course_type_name',
'level_name',
'status_name',
'teacher',
'section_list',
]
# 定制，返回课程的老师，课程章节及章节下的课时（总共课时最多显示4条，不足4条，就全部显示）
# 子序列化 表模型中写，在序列化类中
teacher = TeacherSerializer()
表模型
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)
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)
# 删除某个课程分类，如果使用models.CASCADE，所有课程都删除，很危险
# 删除某个课程分类models.SET_NULL，跟它相关联的课程，置为空
'''on_delete 可以选择的参数
models.CASCADE # 级联删除，注意使用时机，用户和用户详情 课程和课程章节
models.SET_NULL # 删除分类，课程这个字段设置为空，要有null=True参数的配合
models.SET_DEFAULT # 删除分类，课程这个字段设置为默认值，要有 defalut=xx参数的配合
models.DO_NOTHING # 删除分类，课程这个字段什么都不做
models.SET(值,函数内存地址) # 删除分类，课程这个字段设置为写的值，或者执行内部传入的函数，函数返回值放在这
'''
# db_constraint=False 逻辑外键，不建立物理外键 没有外键约束,如果这样设置，修改，新增速度快，可能会出现脏数据（程序层面控制）
# 连表查询没有任何区别，其他操作完全一致
course_category = models.ForeignKey("CourseCategory", on_delete=models.SET_NULL, db_constraint=False, null=True,
blank=True, verbose_name="课程分类")
teacher = models.ForeignKey("Teacher", on_delete=models.DO_NOTHING, null=True, blank=True, verbose_name="授课老师")
class Meta:
db_table = "luffy_course"
verbose_name = "课程"
verbose_name_plural = "课程"
def __str__(self):
return "%s" % self.name
# choice字段，返回中文
def course_type_name(self):
return self.get_course_type_display()
def level_name(self):
return self.get_level_display()
def status_name(self):
return self.get_status_display()
def section_list(self):
l = []
# 先取出课程下所有章节
course_chapter_list = self.coursechapters.all()
for course_chapter in course_chapter_list:
# 拿出这个章节下所有课时
course_section_list = course_chapter.coursesections.all()
for course_section in course_section_list:
l.append({'id': course_section.id,
'name': course_section.name,
'section_type': course_section.section_type,
'section_link': course_section.section_link,
'duration': course_section.duration,
'free_trail': course_section.free_trail,
})
if len(l) >= 4:
return l
# 循环章节，取出每个章节下的课时，追加到l中，如果超过4条，就结束了
return l
分页
class CommonPageNumberPagination(PageNumberPagination):
page_size = 2
page_query_param = 'page'
page_size_query_param = 'size'
max_page_size = 5
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