drf - 排序組件OrderingFilter分析總結

排序組件OrderingFilter

models.py 文件

from django.db import models
class BaseModel(models.Model):
    is_delete = models.BooleanField(default=False)
    create_time = models.DateTimeField(auto_now_add=True)
    class Meta:
        abstract = True
        
class Car(BaseModel):
    name = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    brand = models.ForeignKey('Brand', db_constraint=False, on_delete=models.DO_NOTHING, related_name='cars')
    @property
    def brand_name(self):
        return self.brand.name
    class Meta:
        db_table = 'old_boy_car'
        verbose_name = '汽車'
        verbose_name_plural = verbose_name
    def __str__(self):
        return self.name


class Brand(BaseModel):
    name = models.CharField(max_length=32)
    class Meta:
        db_table = 'old_boy_brand'
        verbose_name = '品牌'
        verbose_name_plural = verbose_name
    def __str__(self):
        return self.name

serializer.py文件

from rest_framework.serializers import ModelSerializer
from . import models
class CarModelSerializer(ModelSerializer):
    class Meta:
        model = models.Car
        fields = ('name','price','brand','brand_name')
        extra_kwargs = {
            "brand":{
                'write_only':True
            },
            'brand_name':{
                'read_only':True
            },
        }

views.py 文件

from rest_framework.viewsets import ModelViewSet
from . import models, serializer
from rest_framework.filters import OrderingFilter

class CarModelViewSet(ModelViewSet):
    queryset = models.Car.objects.filter(is_delete=False)
    serializer_class = serializer.CarModelSerializer
    filter_backends = [OrderingFilter]
    # ordering_fields = ['pk','-price']
    # ordering_fields = '__all__'

總結

# 如果有ordering_fields
    # url輸入的是該字段，就按該字段排序（ordering_fields必須是可以參與order_by()的字段，否則會報錯）否則不排序
    
# 如果ordering_fields = '__all__':
    # 1. 如 url:/ordering = -sdfsfd，則 ordering = None，不排序
    # 2. 如 url:/ordering = -price, 則 ordering = -price，按-price排序
    
# 如果沒有指定ordering_fields,
    # 1. 不參與序列化，如：sdsadf。則 ordering = None，不排序
    # 2. 參與序列化且是表字段，如：price，則 ordering = price, 按price排序，
    # 3. 參與序列化不是表字段，如：brand_name, 則 ordering = brand_name,報錯（order_by(brand_name)出錯）