本帖最后由 武汉分校-小舞 于 2018-12-18 14:34 编辑
Django模型关系建表查询和序列化嵌套使用
模型部分
1.一对一
模型：
class Class(models.Model):
id = models.AutoField(primary_key=True)
cname = models.CharField(max_length=32)
cdata = models.DateField()
def __str__(self):
return self.cname
class Student(models.Model):
id = models.AutoField(primary_key=True)
sname = models.CharField(max_length=32)
# 一对多
# cid = models.ForeignKey(to="Class",to_field="id",related_name="student")
cid = models.ForeignKey(Class, to_field="id",related_name='class_related')
# 一对一
detail = models.OneToOneField(StudentDetail, to_field="id",related_name='detail_related')
# 等同于如下的代码
# detail = models.ForeignKey(to="StudentDetail",to_field="id",unique=True)
class StudentDetail(models.Model):
id = models.AutoField(primary_key=True)
height = models.PositiveIntegerField()
email = models.EmailField()
memo = models.CharField(max_length=128)
查询：
#正向查询（由学生信息表查询学生详情表）
stu = models.Student.objects.first()
stu.detail.email
'234@qq'
#反向查询（由学生详情表反向查询学生信息表）
std = StudentDetail.objects.first()
std.detailtostudent_related
'小明'
2.一对多
模型：
class Class(models.Model):
id = models.AutoField(primary_key=True)
cname = models.CharField(max_length=32)
cdata = models.DateField()
def __str__(self):
return self.cname
class Student(models.Model):
id = models.AutoField(primary_key=True)
sname = models.CharField(max_length=32)
# 一对多
cid = models.ForeignKey(Class, to_field="id",related_name='class_related')
# 一对一
detail = models.OneToOneField(StudentDetail, to_field="id",related_name='detail_related')
查询：
#正向查询
stu = Student.objects.first()
<Student: 小明>
stu.cid
<Class: 火箭1班>
#反向查询
cls = Class.objects.first()
cls.class_related.all()
<QuerySet [<Student: 小明>, <Student: 小花>, <Student: 小王>]>
效果：
{
"sname": "小王",
"cid": {
"cname": "一班",
"cdata": "2018-11-17"
},
"detail": {
"height": 180,
"email": "123@qq.com",
"memo": "lol"
}
},
3.多对多对
效果（查询出当前老师的所有班级和对应的班级的所有学生）：
{
"tname": "王老师",
"classes": [
{
"cname": "一班",
"class_related": [
{
"sname": "小王",
"detail": {
"height": 180,
"email": "123@qq.com",
"memo": "lol"
}
}
]
},
{
"cname": "二班",
"class_related": [
{
"sname": "小刘",
"detail": {
"height": 175,
"email": "234@qq.com",
"memo": "dnf"
}
}
]
},
{
"cname": "三班",
"class_related": [
{
"sname": "小李",
"detail": {
"height": 170,
"email": "345@qq.com",
"memo": "wow"
}
}
]
},
{
"cname": "四班",
"class_related": [
{
"sname": "小赵",
"detail": {
"height": 165,
"email": "456@qq.com",
"memo": "h1z1"
}
}
]
}
]
},
序列化器：
class StudentsSerializer(serializers.ModelSerializer):
detail = StudentDetailSerializer()
class Meta:
model = Student
fields = ('sname','detail')
class ClassSerializer(serializers.ModelSerializer):
#此处可以使用related_name来关联上student表
class_related = StudentsSerializer(many=True)
class Meta:
model = Class
fields = ('cname','class_related')
class TeacherSerializer(serializers.ModelSerializer):
classes = ClassSerializer(many=True)
class Meta:
model = Teacher
fields = ('tname','classes')
视图：
class TeacherView(GenericAPIView):
serializer_class = TeacherSerializer
queryset = Teacher.objects.all()
# renderer_classes = (Utf8JSONRenderer,)
def get(self, request):
data = self.get_queryset()
serializer = self.get_serializer(data, many=True)
return Response(serializer.data)
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