8.courses的model

课程所需要的数据库表有：

1. 存放课程基本信息的
2. 存放课程章节的
3. 存放章节视频的
4. 存放课程资源的
   其中1-2是1对多的关系，2-3也是1对多的关系，1-4也是1对多的关系。django没单独设置一对多或者多对一额映射关系，靠外键ForeignKey实现。models.py:

from django.db import models
from datetime import datetime
# Create your models here.


class Course(models.Model):
    name = models.CharField(max_length=50, verbose_name="课程名")
    desc = models.CharField(max_length=300, verbose_name="课程描述")
    detail = models.TextField(verbose_name="课程详情")
    degree = models.CharField(choices=(("cj","初级"),("zj","中级"), ("gj","高级")),max_length=10)
    learn_times = models.IntegerField(default=0, verbose_name="学习时长（分钟数）")
    students = models.IntegerField(default=0,verbose_name="学习人数")
    fav_nums= models.IntegerField(default=0, verbose_name="收藏人数")
    image = models.ImageField(upload_to="courses/%Y/%m", verbose_name="封面")
    click_nums = models.IntegerField(default = 0, verbose_name="点击数")
    add_time = models.DateTimeField(default=datetime.now, verbose_name="添加时间")

    class Meta:
        verbose_name = "课程"
        verbose_name_plural = verbose_name


class Lesson(models.Model):
    course = models.ForeignKey(Course,verbose_name="课程")
    name = models.CharField(max_length=100, verbose_name="章节名")
    add_time = models.DateTimeField(default=datetime.now, verbose_name="添加时间")

    class Meta:
            verbose_name = "章节"
            verbose_name_plural = verbose_name


class Video(models.Model):
    lesson = models.ForeignKey(Lesson, verbose_name="章节")
    name = models.CharField(max_length=100, verbose_name="视频名")
    add_time = models.DateTimeField(default=datetime.now, verbose_name="添加时间")

    class Meta:
            verbose_name = "视频"
            verbose_name_plural = verbose_name


class CoursesResources(models.Model):
    course = models.ForeignKey(Course, verbose_name="课程")
    name = models.CharField(max_length=100, verbose_name="名称")
    download = models.FileField(upload_to="course/resource/%Y/%m", verbose_name="资源文件")
    add_time = models.DateTimeField(default=datetime.now, verbose_name="添加时间")

    class Meta:
            verbose_name = "课程资源"
            verbose_name_plural = verbose_name

可以大致看到外间的用法。
course = models.ForeignKey(Course, verbose_name="课程")
括号里先是对应的表格（类）名，然后再起个名字~