errors.invalid_query_parse_error=La requête donnée n'est pas valide.
errors.invalid_query_sort_value=Le tri donné ({0}) n'est pas valide.
errors.invalid_query_unsupported_sort_field=Le tri donné ({0}) n'est pas pris en charge.
errors.invalid_query_unsupported_sort_order=L'ordre de tri donné ({0}) n'est pas pris en charge.

errors.crud_invalid_mode=Mode invalide (la valeur attendue est {0}, mais c'est {1}).

{*../../docs_src/python_types/tutorial009.py hl[1,4] *}

Utiliser `Optional[str]` plutôt que `str` permettra à l'éditeur de vous aider à détecter les erreurs où vous supposeriez qu'une valeur est toujours de type `str`, alors qu'elle pourrait aussi être `None`.

#### Types génériques

                    "loc": ["body", "username"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "password"],
                    "msg": "Field required",
                    "input": None,
                },
            ]
        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1

                    "loc": ["body", "username"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "password"],
                    "msg": "Field required",
                    "input": None,
                },
            ]
        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1

                    "loc": ["body", "username"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "password"],
                    "msg": "Field required",
                    "input": None,
                },
            ]
        }
    ) | IsDict(

from typing import Union

from fastapi import APIRouter, FastAPI
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Invoice(BaseModel):
    id: str
    title: Union[str, None] = None
    customer: str
    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool


invoices_callback_router = APIRouter()

```

기본값 `None`을 `Query(None)`으로 바꿔야 하므로, `Query`의 첫 번째 매개변수는 기본값을 정의하는 것과 같은 목적으로 사용됩니다.

그러므로:

```Python
q: Optional[str] = Query(None)
```

...위 코드는 아래와 동일하게 매개변수를 선택적으로 만듭니다:

```Python
q: Optional[str] = None
```

하지만 명시적으로 쿼리 매개변수를 선언합니다.

/// info | "정보"

FastAPI는 다음 부분에 관심이 있습니다:

```Python
= None
```

또는:

```Python
= Query(None)

from sqlmodel import Field, Session, SQLModel, create_engine, select


class Hero(SQLModel, table=True):
    id: Union[int, None] = Field(default=None, primary_key=True)
    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)
    secret_name: str


sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},
    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}

from sqlmodel import Field, Session, SQLModel, create_engine, select
from typing_extensions import Annotated


class Hero(SQLModel, table=True):
    id: Union[int, None] = Field(default=None, primary_key=True)
    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)
    secret_name: str


sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"