首页 > 技术文章 > 首页轮播图异步更新、课程表结构分析和优化、课程主页页面、课程数据准备、课程分类群查接口、课程群查接口、搜索组件和过滤、自定义过滤类

0B0S 2020-09-05 14:28 原文

# 1 首页轮播图异步更新

```python


# celery.py
from celery import Celery

# 加载django环境
import os
import django
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "luffyapi.settings.dev")
django.setup()

broker='redis://127.0.0.1:6379/1' #broker任务队列
backend='redis://127.0.0.1:6379/2' # 结构存储,执行完的结果存在这

app=Celery(__name__,broker=broker,backend=backend,include=['celery_task.home_task',])


# 执行定时任务
# 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': {
'task': 'celery_task.home_task.banner_update',
'schedule': timedelta(seconds=30),
}
}


# home_task.py
from .celery import app
@app.task
def banner_update():
from home import serializer
from home import models
from django.conf import settings
from django.core.cache import cache
queryset_banner = models.Banner.objects.filter(is_delete=False, is_show=True).order_by('display_order')[
:settings.BANNER_COUNTER]
serializer_banner=serializer.BannerModelSerilaizer(instance=queryset_banner,many=True)
# print(serializer_banner.data)
for banner in serializer_banner.data:
banner['img']='http://127.0.0.1:8000'+banner['img']
cache.set('banner_list',serializer_banner.data)
# import time
# time.sleep(1)
# banner_list=cache.get('banner_list')
# print(banner_list)
return True
```


## 2 课程表结构分析和优化

```python
# ForeignKey的字段:
-related_name 反向操作时,使用的字段名,用于代替原反向查询时的'表名_set'。
-related_query_name :反向查询操作时,使用的连接前缀,用于替换表名。

################1 course/models.py
from luffyapi.utils.models import BaseModel
# 实际路飞课程相关表,以免费课为例
class CourseCategory(BaseModel):
"""分类
python,linux,go, 网络安全
跟课程是一对多的关系

"""
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


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'),
)
# 原始字段
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")
# 使用这个字段的原因
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")
price = models.DecimalField(max_digits=6, decimal_places=2, verbose_name="课程原价", default=0)

# 优化字段
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)

# 关联字段
teacher = models.ForeignKey("Teacher", on_delete=models.DO_NOTHING, null=True, blank=True, verbose_name="授课老师",db_constraint=False)
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


class Teacher(BaseModel):
"""导师
跟课程一对多,关联字段写在课程表中
"""
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


class CourseChapter(BaseModel):
"""章节
章节跟课程是一(课程)对多(章节多)
"""
course = models.ForeignKey("Course", related_name='coursechapters', on_delete=models.CASCADE, verbose_name="课程名称",db_constraint=False)
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)


class CourseSection(BaseModel):
"""课时
章节和课时是一对多的关系,关联字段写在多的一方,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",db_constraint=False)
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)


################2 utils/models/BaseModel
from django.db import models
# 后期课程表,轮播图表,都会用到这些字段

class BaseModel(models.Model):
is_delete = models.BooleanField(default=False, verbose_name='是否删除')
is_show = models.BooleanField(default=True, verbose_name='是否展示')
# 修改成这样
created_time = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
updated_time = models.DateTimeField(auto_now=True, verbose_name='最后更新时间')
orders = models.IntegerField()
class Meta:
abstract=True # 一定不要忘了


################3 数据迁移
python manage.py makemigrations
python manage.py migrate

```

## 3 课程主页页面

```python
# 不要忘了注册路由

# FreeCourse.vue
<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/Head"
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>
```


## 4 课程数据准备

```sql



-- 老师表
-- 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, '2019-07-14 13:44:19.661327', '2019-07-14 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, '2019-07-14 13:45:25.092902', '2019-07-14 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, '2019-07-14 13:46:21.997846', '2019-07-14 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');

-- 课程分类表
-- INSERT INTO luffy_course_category(id, orders, is_show, is_delete, created_time, updated_time, name) VALUES (1, 1, 1, 0, '2019-07-14 13:40:58.690413', '2019-07-14 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, '2019-07-14 13:41:08.249735', '2019-07-14 13:41:08.249817', 'Linux');


-- 课程表数据
-- 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, '2019-07-14 13:54:33.095201', '2019-07-14 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, '2019-07-14', 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, '2019-07-14 13:56:05.051103', '2019-07-14 13:56:05.051142', 'Python项目实战', 'courses/mjj_python.png', 0, '', 1, '2019-07-14', 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, '2019-07-14 13:57:21.190053', '2019-07-14 13:57:21.190095', 'Linux系统基础5周入门精讲', 'courses/lyy_linux.png', 0, '', 0, '2019-07-14', 25, '', 0, 219, 100, 100, 39.00, 2, 3);
--
--


-- 章节表数据
-- 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, '2019-07-14 13:58:34.867005', '2019-07-14 14:00:58.276541', 1, '计算机原理', '', '2019-07-14', 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, '2019-07-14 13:58:48.051543', '2019-07-14 14:01:22.024206', 2, '环境搭建', '', '2019-07-14', 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, '2019-07-14 13:59:09.878183', '2019-07-14 14:01:40.048608', 1, '项目创建', '', '2019-07-14', 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, '2019-07-14 13:59:37.448626', '2019-07-14 14:01:58.709652', 1, 'Linux环境创建', '', '2019-07-14', 3);


-- 课时表数据
-- 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, '2019-07-14 14:02:33.779098', '2019-07-14 14:02:33.779135', '计算机原理上', 1, 2, NULL, NULL, '2019-07-14 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, '2019-07-14 14:02:56.657134', '2019-07-14 14:02:56.657173', '计算机原理下', 2, 2, NULL, NULL, '2019-07-14 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, '2019-07-14 14:03:20.493324', '2019-07-14 14:03:52.329394', '环境搭建上', 1, 2, NULL, NULL, '2019-07-14 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, '2019-07-14 14:03:36.472742', '2019-07-14 14:03:36.472779', '环境搭建下', 2, 2, NULL, NULL, '2019-07-14 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, '2019-07-14 14:04:19.338153', '2019-07-14 14:04:19.338192', 'web项目的创建', 1, 2, NULL, NULL, '2019-07-14 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, '2019-07-14 14:04:52.895855', '2019-07-14 14:04:52.895890', 'Linux的环境搭建', 1, 2, NULL, NULL, '2019-07-14 14:04:52.895942', 1, 4);
```


## 5 课程分类群查接口

```python
# 路由
router = SimpleRouter()
router.register('categories', views.CourseCategoryView, 'categories')
router.register('free', views.CouresView, 'free')
urlpatterns = [
path('', include(router.urls)),
]

# 视图views.py
from rest_framework.viewsets import GenericViewSet
from rest_framework.mixins import ListModelMixin
from . import models
from . import serializer
class CourseCategoryView(GenericViewSet,ListModelMixin):
queryset = models.CourseCategory.objects.filter(is_delete=False,is_show=True).order_by('orders')
serializer_class = serializer.CourseCategorySerializer

# 序列化类
from rest_framework import serializers
from . import models
class CourseCategorySerializer(serializers.ModelSerializer):
class Meta:
model=models.CourseCategory
fields=['id','name']
```


## 6 课程群查接口
```python
# 路由
router = SimpleRouter()
router.register('categories', views.CourseCategoryView, 'categories')
router.register('free', views.CouresView, 'free')
urlpatterns = [
path('', include(router.urls)),
]

# 视图 views.py
from .paginations import PageNumberPagination
from django_filters.rest_framework import DjangoFilterBackend
from rest_framework.filters import OrderingFilter,SearchFilter
from .filters import MyFilter
class CouresView(GenericViewSet,ListModelMixin,RetrieveModelMixin):
queryset = models.Course.objects.filter(is_delete=False,is_show=True).order_by('orders')
serializer_class = serializer.CourseModelSerializer
pagination_class = PageNumberPagination
filter_backends=[DjangoFilterBackend,OrderingFilter]
ordering_fields=['id', 'price', 'students']

filter_fields=['course_category','students']

###serializer
from rest_framework import serializers
from . import models


class CourseCategorySerializer(serializers.ModelSerializer):
class Meta:
model = models.CourseCategory
fields = ['id', 'name']


class TeacherSerializer(serializers.ModelSerializer):
class Meta:
model = models.Teacher
fields = ('name', 'role_name', 'title', 'signature', 'image', 'brief')


class CourseModelSerializer(serializers.ModelSerializer):
# 子序列化的方式
teacher = TeacherSerializer()

class Meta:
model = models.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',
]
# models.py
class Course(BaseModel):
...
@property
def course_type_name(self):
return self.get_course_type_display()
@property
def level_name(self):
return self.get_level_display()
@property
def status_name(self):
return self.get_status_display()

@property
def section_list(self):
ll=[]
# 根据课程取出所有章节(正向查询,字段名.all())
course_chapter_list=self.coursechapters.all()
for course_chapter in course_chapter_list:
# 通过章节对象,取到章节下所有的课时(反向查询)
# course_chapter.表名小写_set.all() 现在变成了course_chapter.coursesections.all()
course_sections_list=course_chapter.coursesections.all()
for course_section in course_sections_list:
ll.append({
'name': course_section.name,
'section_link': course_section.section_link,
'duration': course_section.duration,
'free_trail': course_section.free_trail,
})
if len(ll)>=4:
return ll

return ll



class Teacher(BaseModel):
...
def role_name(self):
# 返回角色的中文
return self.get_role_display()
```

## 7 搜索组件和过滤

```python
'''
排序:
按id正序倒叙排序,按price正序倒叙排列
使用:http://127.0.0.1:8000/course/free/?ordering=-id
配置类:
filter_backends=[OrderingFilter]
配置字段:
ordering_fields=['id','price']


内置过滤:
使用:http://127.0.0.1:8000/course/free/?search=39
按照price过滤(表自有的字段直接过滤)
配置类:
filter_backends=[SearchFilter]
配置字段:
search_fields=['price']

扩展:django-filter
安装:
支持自由字段的过滤还支持外键字段的过滤
http://127.0.0.1:8000/course/free/?course_category=1 # 过滤分类为1 (python的所有课程)
配置类:
filter_backends=[DjangoFilterBackend]
配置字段:
filter_fields=['course_category']


'''
```

## 9 自定义过滤类

```python
# filters.py
# 自定义过滤规则
from rest_framework.filters import BaseFilterBackend

class MyFilter(BaseFilterBackend):
def filter_queryset(self, request, queryset, view):
# 真正的过滤规则
# params=request.GET.get('teacher')
# queryset.filter('''''')
return queryset[:1]

# 使用:在视图类中配置
filter_backends=[DjangoFilterBackend,OrderingFilter,MyFilter]
```

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