Question

我想要一个多层次的嵌套序列化器。基本上，每所学校都有一个学生名单，每个学生都有一个成绩清单。它正在输出

{"id":1,"name":"Sierra Grande Elem/Junior High"}

并且看起来它不包括我创建的任何嵌套。

这是我的模型。py

class School(models.Model):
    name = models.TextField(max_length = 150, blank=True)

class Student(models.Model):
    current_school = models.ForeignKey(
        "School",
        null = True,
        on_delete = models.PROTECT,
    )
    first_name = models.CharField(max_length = 35, blank=True)
    last_name = models.CharField(max_length = 35, blank=True)


class Grade(models.Model):
    student = models.ForeignKey(
        "Student",
        null = True,
        on_delete = models.PROTECT,
    )
    course = models.ForeignKey(
        "Course",
        null = True,
        on_delete = models.PROTECT,
    )
    grade = models.FloatField(null = True)

这是我的serializers.py

class NestedSchoolSerializer(serializers.ModelSerializer):
    class Meta:
        model = School
        fields = ("id","name")

class NestedStudentSerializer(serializers.ModelSerializer):
    school_set = NestedSchoolSerializer(many = True, read_only = True)
    class Meta:
        model = Student
        fields = ("school_set","id","first_name","last_name")


class NestedGradeSerializer(serializers.ModelSerializer):
    student_set = NestedStudentSerializer(many = True, read_only = True)
    class Meta: 
        model = Grade
        fields = ("student_set","id","course","grade")

这是我的views.py文件：

class SchoolInfo(generics.RetrieveAPIView):
    queryset = School.objects.all()
    serializer_class = NestedSchoolSerializer

这是我的url.py文件：

urlpatterns = [
    path('school/grade/<int:pk>/', views.SchoolInfo.as_view()),
  ]

非常感谢您的帮助！ Django的新手，在相当长的一段时间内一直无法解决这个问题。我需要更改代码的哪一部分？

Answer 1

欢迎堆栈溢出！看起来您走在正确的轨道上，但是嵌套却倒置了。您的NestedSchoolSerializer对学生一无所知，而NestedStudentSerializer对成绩也不知道。可能还有其他问题，但这是第一个跳出来问我的问题。尝试这样的事情：

class NestedGradeSerializer(serializers.ModelSerializer):
    class Meta: 
        model = Grade
        fields = ("id","course","grade")

class NestedStudentSerializer(serializers.ModelSerializer):
    grade_set = NestedGradeSerializer(many = True, read_only = True)
    class Meta:
        model = Student
        fields = ("grade_set","id","first_name","last_name")


class NestedSchoolSerializer(serializers.ModelSerializer):
    student_set = NestedStudentSerializer(many = True, read_only = True)
    class Meta:
        model = School
        fields = ("id", "name", "student_set")

知道如何设置这些内容的一种方法是，在大多数情况下，序列化程序中的字段应映射到同一模型中的字段（如果您使用的是ModelSerializer）。

Django Rest Framework-嵌套序列化不嵌套

1 个答案: