在這種情況下（未使用 `Annotated`），我們必須用 `Query()` 取代函式中的預設值 `None`，因此需要用 `Query(default=None)` 來設定預設值；對 FastAPI 而言，這達到相同目的。

所以：

```Python
q: str | None = Query(default=None)
```

…會讓參數變為可選、預設值是 `None`，等同於：

```Python
q: str | None = None
```

但用 `Query` 的版本會明確宣告它是查詢參數。

接著，我們可以傳更多參數給 `Query`。此例中是用於字串的 `max_length` 參數：

```Python
q: str | None = Query(default=None, max_length=50)
```

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["body", "p"],
                "msg": "Field required",
                "input": None,
            }
        ]
    }


@pytest.mark.parametrize(
    "path",
    [
        "/list-bytes",
        "/list-uploadfile",
    ],
)
def test_list(path: str):

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


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


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

        @app.get("/query_example/")
        def query_example(
            data: str | None = Query(
                default=None,
                example="query1",
            ),
        ):
            return data

    @app.get("/query_examples/")
    def query_examples(
        data: str | None = Query(
            default=None,
            examples=["query1", "query2"],
        ),
    ):
        return data

    type: SchemaType | list[SchemaType] | None = None
    enum: list[Any] | None = None
    const: Any | None = None
    multipleOf: float | None = Field(default=None, gt=0)
    maximum: float | None = None
    exclusiveMaximum: float | None = None
    minimum: float | None = None
    exclusiveMinimum: float | None = None
    maxLength: int | None = Field(default=None, ge=0)
    minLength: int | None = Field(default=None, ge=0)

@app.post("/optional-list-bytes")
async def read_optional_list_bytes(p: Annotated[list[bytes] | None, File()] = None):
    return {"file_size": [len(file) for file in p] if p else None}


@app.post("/optional-list-uploadfile")
async def read_optional_list_uploadfile(
    p: Annotated[list[UploadFile] | None, File()] = None,
):
    return {"file_size": [file.size for file in p] if p else None}


@pytest.mark.parametrize(
    "path",
    [

		for i := range erasureDisks[:8] {
			erasureDisks[i] = nil
		}
		return erasureDisks
	}
	z.serverPools[0].erasureDisksMu.Unlock()

	t.Run("if-none-match with read quorum failure", func(t *testing.T) {
		// Test Case 1: if-none-match (create only if doesn't exist)
		// With if-none-match: *, this should only succeed if object doesn't exist.
		// Since read quorum fails, we can't determine if object exists.
		opts := ObjectOptions{

# Without aliases


@app.post("/optional-list-str", operation_id="optional_list_str")
async def read_optional_list_str(
    p: Annotated[list[str] | None, Body(embed=True)] = None,
):
    return {"p": p}


class BodyModelOptionalListStr(BaseModel):
    p: list[str] | None = None


@app.post("/model-optional-list-str", operation_id="model_optional_list_str")
async def read_model_optional_list_str(p: BodyModelOptionalListStr):

# Without aliases


@app.get("/optional-str")
async def read_optional_str(p: Annotated[str | None, Header()] = None):
    return {"p": p}


class HeaderModelOptionalStr(BaseModel):
    p: str | None = None


@app.get("/model-optional-str")
async def read_model_optional_str(p: Annotated[HeaderModelOptionalStr, Header()]):
    return {"p": p.p}

async def override_dependency(q: str | None = None):
    return {"q": q, "skip": 5, "limit": 10}


app.dependency_overrides[common_parameters] = override_dependency


def test_override_in_items():
    response = client.get("/items/")
    assert response.status_code == 200
    assert response.json() == {
        "message": "Hello Items!",
        "params": {"q": None, "skip": 5, "limit": 10},
    }