Pydantic, sqlalchemy, fastapi, 'pydantic.error_wrappers.ValidationError: 1 validation error for' [duplicate] - python-3.x

Question

I'm making a crud in fastapiI have a user model and I created another one called showuser to only show some specific fields in the query, but when I execute the request I get an error.
I just want my request to show the fields I have in showuser.
my schemas
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
and this is the code from user where I implement the api
#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}
Terminal Message
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)

Answer 1

I think the return value of your get_user function is the issue. Rather than returning {"User": user}, try returning just the user object as shown below:
#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
EDIT: The same error will occur if the database does not contain a User object matching the value of user_id. Rather than returning {"Error": "User not found"}, the best way to handle this very common scenario is to raise an HTTPException with a 404 status code and error message:
#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