flask数据库查询之反向引用

反向引用

模型字段名

class Brand(BaseModel,db.Model):
    __tablename__ = 'brand'
    # id=db.Column(db.Integer,primary_key=True)
    brand_name=db.Column(db.String(20))
    brand_style=db.Column(db.String(30))
    brand_style_detail=db.Column(db.String(50))
    cars=db.relationship('Car',backref='brand')
    def __repr__(self):
        return self.brand_name

class Car(BaseModel,db.Model):
    __tablename__='sc_cars'
    # id=db.Column(db.Integer,primary_key=True)
    user_id=db.Column(db.Integer,db.ForeignKey('sc_users.id'))
    brand_id=db.Column(db.Integer,db.ForeignKey('brand.id'))
    price= db.Column(db.Integer,default=0,nullable=False)
    car_age=db.Column(db.Integer) #age of the car
    car_style=db.Column(db.String(10))#style of the car
    car_gearbox=db.Column(db.Integer,default=0)#0 for hand,1 for auto
    car_distance=db.Column(db.Integer)
    car_displacement=db.Column(db.Float)
    car_register_time=db.Column(db.DateTime)
    car_num=db.Column(db.String(100))
    car_color=db.Column(db.String(10))
    car_oil_type=db.Column(db.String(10))
    car_emission_standard=db.Column(db.String(10))
    seat_num=db.Column(db.Integer)
    transfer_time=db.Column(db.Integer)
    inspect_annually=db.Column(db.String(10))
    traffic_compulsory_insurance=db.Column(db.String(10))
    commercial_insurance=db.Column(db.String(10))
    images=db.relationship('Carimg',backref='img')
    index_image_url=db.Column(db.String(100))

    orders=db.relationship('Order',backref='orders')

    def to_list_dict(self):
        # newdict = {}
        # brand_obj = each.brand
        # newdict['brand'] = brand_obj.brand_name
        # newdict['carstyle'] = brand_obj.brand_style
        # newdict['carstyle_detail'] = brand_obj.brand_style_detail
        # newdict['car_register_time'] = each.car_register_time
        # newdict['price'] = each.price
        # newdict['car_distance'] = each.car_distance

        car_obj_dict={
            'brand':self.brand.brand_name,
            'carstyle':self.brand.brand_style,
            'carstyle_detail':self.brand.brand_style_detail,
            'car_register_time':self.car_register_time,
            'price':self.price,
            'car_distance':self.car_distance
        }
        return car_obj_dict

反向引用

比较普通引用