如何响应FastAPI中的关系数据？

Question

我正在使用FastApi进行后端，其中有两个模式

import datetime as dt
from typing import Optional
from pydantic import BaseModel, Field


class TradeDetails(BaseModel):
    buySellIndicator: str = Field(description="A value of BUY for buys, SELL for sells.")
    price: float = Field(description="The price of the Trade.")
    quantity: int = Field(description="The amount of units traded.")

    class Config:
        orm_mode = True


class Trade(BaseModel):
    asset_class: Optional[str] = Field(alias="assetClass", default=None,
                                       description="The asset class of the instrument traded. E.g. Bond, Equity, FX...etc")
    counterparty: Optional[str] = Field(default=None,
                                        description="The counterparty the trade was executed with. May not always be available")
    instrument_id: str = Field(alias="instrumentId",
                               description="The ISIN/ID of the instrument traded. E.g. TSLA, AAPL, AMZN...etc")
    instrument_name: str = Field(alias="instrumentName", description="The name of the instrument traded.")
    trade_date_time: dt.datetime = Field(alias="tradeDateTime", description="The date-time the Trade was executed")
    trade_details: TradeDetails = Field(alias="tradeDetails",
                                        description="The details of the trade, i.e. price, quantity")
    trade_id: str = Field(alias="tradeId", default=None, description="The unique ID of the trade")
    trader: str = Field(description="The name of the Trader")

    class Config:
        orm_mode = True

，对于这两个模式，我在数据库中创建了两个与关系的表，

from sqlalchemy import Column, Integer, String, Float, DateTime, ForeignKey
from sqlalchemy.orm import relationship

from database import Base


class TradeDetails(Base):
    __tablename__ = "trade_details"

    id = Column(Integer, primary_key=True, index=True)
    buySellIndicator = Column(String)
    price = Column(Float)
    quantity = Column(Integer)
    trades = relationship("Trade", back_populates='trade_details')


class Trade(Base):
    __tablename__ = "trade"

    trade_id = Column(String, primary_key=True, index=True)
    trader = Column(String)
    trade_details_id = Column(Integer, ForeignKey("trade_details.id"))
    trade_details = relationship("TradeDetails", back_populates='trades')
    asset_class = Column(String)
    counterparty = Column(String)
    instrument_id = Column(Integer)
    instrument_name = Column(String)
    trade_date_time = Column(DateTime)

现在我正在执行CRUD操作。

当我试图创造贸易时，请求身体的样子

但是，当我执行创建贸易响应的邮政方法时在贸易模型中

我用来发布的方法

我正在犯的错误是什么，让我知道，我该如何解决此问题？