I recently started studyingfastapi and can’t serialize response schema.

Got two model object, but I could not bring it to a specific scheme.

Without using response_model, I just get the following response:

{
  "OcProduct": {

    "viewed": 617,
    "product_id": 160,
    "model": "name",
    "stock_status_id": 6,
    "image": "catalog/product/test.jpg",
    "status": 1
  },
  "OcStockStatu": {
    "name": "Out Of Stock",
    "language_id": 2,
    "stock_status_id": 6
  }
}

But I want to get this:

{
    "viewed": 617,
    "product_id": 160,
    "model": "name",
    "stock_status_id": 6,
    "image": "catalog/product/test.jpg",
    "status": 1,
    "name": "Out Of Stock"
}

orm_product.py

def get_product_by_id(product_id: int, db: Session):
    return db.query(OcProduct, OcStockStatu).join(OcStockStatu, OcProduct.stock_status_id == OcStockStatu.stock_status_id).filter(OcProduct.product_id == product_id).first()

models.py

class OcProduct(Base):
    __tablename__ = 'oc_product'

    product_id = Column(Integer, primary_key=True)
    model = Column(String(64), nullable=False)
    stock_status_id = Column(Integer, nullable=False)
    image = Column(String(255))
    status = Column(TINYINT(1), nullable=False, server_default=text("'0'"))
    viewed = Column(Integer, nullable=False, server_default=text("'0'"))

class OcStockStatu(Base):
    __tablename__ = 'oc_stock_status'

    stock_status_id = Column(Integer, primary_key=True, nullable=False)
    language_id = Column(Integer, primary_key=True, nullable=False)
    name = Column(String(32), nullable=False)

scheme_product.py

class DetailProduct(BaseModel):

    product_id: int
    model: str
    image: str
    price: float
    name: str

    class Config:
        orm_mode = True

product.py

@router.get("/product/{id}", response_model=scheme_product.DetailProduct)
def get_detail_product(id: int, db: Session = Depends(get_db)):
    product = orm_product.get_product_by_id(id, db)
    .......
    return product

With the given schema, I get the following exception:

Output

raise ValidationError(errors, field.type_)
pydantic.error_wrappers.ValidationError: 5 validation errors for DetailProduct
response -> product_id
  field required (type=value_error.missing)
response -> model
  field required (type=value_error.missing)
response -> image
  field required (type=value_error.missing)
response -> price
  field required (type=value_error.missing)
response -> name
  field required (type=value_error.missing)

How can I solve this problem?

>Solution :

While writing query mention the fields you want.

Example

db.query(OcProduct.field1, OcProduct.field2, OcStockStatu.field1, OcStockStatu.field2).join(OcStockStatu, OcProduct.stock_status_id == OcStockStatu.stock_status_id).filter(OcProduct.product_id == product_id).first()

field1 and field2 are examples. Select fields which you want from related table as above. (product_id, model and so on.)