pydantic.error_wrappers.ValidationError：FastAPI

我正在 fastapi 中进行增删改查，我有一个用户模型，并且创建了另一个名为 showuser 的模型，以仅显示查询中的某些特定字段，但是当我执行请求时，出现错误。

我只是希望我的请求显示我在 showuser 中拥有的字段。

我的模式

from pydantic import BaseModel
from typing import Optional
from datetime import datetime

# Create a User model
# Create a class for the user


class User(BaseModel):
    username: str
    password: str
    name: str
    lastname: str
    address: Optional[str] = None
    telephone: Optional[int] = None
    email: str
    creation_user: datetime = datetime.now()

# Create UserId model
# Create a class for the UserId
class UserId(BaseModel):
    id: int

# Create a ShowUser model
# Create a class for the ShowUser
class ShowUser(BaseModel):
    username: str
    name: str
    lastname: str
    email: str
    class Config():
        orm_mode = True

这是我实现 api 的用户代码

@router.get('/{user_id}', response_model=ShowUser)
def get_user(user_id: int, db: Session = Depends(get_db)):
    user = db.query(models.User).filter(models.User.id == user_id).first()
    if not user:
        return {"Error": "User not found"}
    return {"User": user}

终端消息

pydantic.error_wrappers.ValidationError: 4 validation errors for ShowUser 
response -> username
  field required (type-value_error.missing)
response -> name
  field required (type=value_error.missing) 
response -> lastname
  field required (type=value_error.missing) 
response -> email
  field required (type=value_error.missing)

我认为你的返回值get_user功能是问题。而不是返回{"User": user}，尝试仅返回user对象如下图所示：

@router.get('/{user_id}', response_model=ShowUser)
def get_user(user_id: int, db: Session = Depends(get_db)):
    user = db.query(models.User).filter(models.User.id == user_id).first()
    if not user:
        return {"Error": "User not found"}
    return user

编辑：如果数据库不包含，则会发生相同的错误User与值匹配的对象user_id。而不是返回{"Error": "User not found"}，处理这种非常常见的情况的最佳方法是提出HTTPException with a 404状态码和错误信息：

@router.get('/{user_id}', response_model=ShowUser)
def get_user(user_id: int, db: Session = Depends(get_db)):
    user = db.query(models.User).filter(models.User.id == user_id).first()
    if not user:
        raise HTTPException(
            status_code=int(HTTPStatus.NOT_FOUND),
            detail=f"No user exists with user.id = {user_id}"
        )
    return user