Django中实现单表和多表接口

基础接口

序列化：course/serializers.py

from rest_framework import serializers
from .models import CourseCategory, Course, Teacher

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

class TeacherSerializer(serializers.ModelSerializer):
    """课程列表的老师信息"""
    class Meta:
        model = Teacher
        fields = ["id", "name", "role", "title", "signature", "brief", "image"]

class CourseSerializer(serializers.ModelSerializer):
    """课程列表的课程基本信息"""
    # 序列化器嵌套[被嵌套的序列化器必须声明对应的字段为模型原有的外键字段，同时这个被嵌套的序列化器必须先声明才能进行调用！]
    # 如果嵌套的序列化器数据有多条，则需要在调用序列化器时需要声明 many=True
    teacher = TeacherSerializer()
    class Meta:
        model = Course
        fields = ["id", "name", "course_img", "students", "sections", "pub_sections", "price", "teacher", 'section_list]

视图：course/views.py

from rest_framework.generics import ListAPIView
from .models import CourseCategory, Course
from .serializers import CourseCategorySerializer, CourseSerializer
class CourseCategoryAPIView(ListAPIView):
    """课程分类列表接口"""
    queryset = CourseCategory.objects.filter(is_delete=False,is_show=True).order_by("orders")
    serializer_class = CourseCategorySerializer

class CourseAPIView(ListAPIView):
    """课程列表接口"""
    queryset = Course.objects.filter(is_delete=False, is_show=True).order_by("orders")
    serializer_class = CourseSerializer

路由：course/urls.py

from django.urls import path,re_path
from . import views
urlpatterns = [
    path("", views.CourseAPIView.as_view()),
    path("category/", views.CourseCategoryAPIView.as_view()),
]

接口

http://127.0.0.1:8000/course/
http://127.0.0.1:8000/course/category/

连表接口

模型演变：course/models.py

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="course", 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")
    course_category = models.ForeignKey("CourseCategory", on_delete=models.SET_NULL, db_constraint=False, null=True, blank=True,
                                        verbose_name="课程分类")
    students = models.IntegerField(verbose_name="学习人数", default=0)
    lessons = models.IntegerField(verbose_name="总课时数量", default=0)
    pub_lessons = 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)
    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

    @property
    def teacher_name(self):
        """返回老师姓名"""
        return self.teacher.name

    @property
    def section_list(self):
        """课程列表的推荐课时"""
        # 获取当前课程的所有章节
        coursechapter_list = self.coursechapters.filter(is_show=True, is_delete=False).order_by("orders")
        # 通过循环当前磕碜的所有章节，来获取章节下面的所有课时
        data_list = []
        for coursechapter in coursechapter_list:
            # 当前章节下的所有课时
            coursesection_list = coursechapter.coursesections.filter(is_show=True, is_delete=False).order_by("orders")
            # 循环每一个课时，逐个追加到data_list进行返回
            for coursesection in coursesection_list:
                if len(data_list) >= 4:
                    break
                data_list.append({
                    "id": coursesection.id,
                    "name": coursesection.name,
                    "free_trail": coursesection.free_trail,
                })

        return data_list

序列化演变：course/serializers.py

class CourseSerializer(serializers.ModelSerializer):
    """课程列表的课程基本信息"""
    # 序列化器嵌套[被嵌套的序列化器必须声明对应的字段为模型原有的外键字段，同时这个被嵌套的序列化器必须先声明才能进行调用！]
    # 如果嵌套的序列化器数据有多条，则需要在调用序列化器时需要声明 many=True
    teacher = TeacherSerializer()

    class Meta:
        model = Course
        fields = ["id", "name", "course_img", "students", "sections", "pub_sections", "price", "teacher", 'section_list]