def query_example(
            data: Union[str, None] = Query(
                default=None,
                example="query1",
            ),
        ):
            return data

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

                            "examples": {
                                "Query One": {
                                    "summary": "Query One Summary",
                                    "description": "Query One Description",
                                    "value": "query1",
                                },
                                "Query Two": {"value": "query2"},
                            },
                        }

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

Dies wird die Daten validieren, einen klaren Fehler anzeigen, wenn die Daten nicht gültig sind, und den Parameter in der OpenAPI-Schema-*Pfadoperation* dokumentieren.

### `Query` als Defaultwert oder in `Annotated` { #query-as-the-default-value-or-in-annotated }

                    },
                    "summary": "Get Query",
                    "operationId": "get_query_query_get",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Query"},
                            "name": "query",
                            "in": "query",
                        }
                    ],

import pytest
from dirty_equals import IsOneOf
from fastapi import FastAPI, Query
from fastapi.testclient import TestClient
from pydantic import BaseModel, Field

app = FastAPI()

# =====================================================================================
# Without aliases


@app.get("/required-list-str")
async def read_required_list_str(p: Annotated[list[str], Query()]):
    return {"p": p}

    response = client.get("/items/", params={"item-query": "nonregexquery"})
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "string_pattern_mismatch",
                "loc": ["query", "item-query"],
                "msg": "String should match pattern '^fixedquery$'",
                "input": "nonregexquery",

# Alias


@app.get("/required-alias")
async def read_required_alias(p: Annotated[str, Query(alias="p_alias")]):
    return {"p": p}


class QueryModelRequiredAlias(BaseModel):
    p: str = Field(alias="p_alias")


@app.get("/model-required-alias")
async def read_model_required_alias(p: Annotated[QueryModelRequiredAlias, Query()]):
    return {"p": p.p}


@pytest.mark.parametrize(
    "path",

def test_query_params_str_validations_q_query(client: TestClient):
    response = client.get("/items/", params={"q": "query"})
    assert response.status_code == 200
    assert response.json() == {
        "items": [{"item_id": "Foo"}, {"item_id": "Bar"}],
        "q": "query",
    }


def test_query_params_str_validations_q_too_short(client: TestClient):
    response = client.get("/items/", params={"q": "qu"})

import pytest
from fastapi import FastAPI, Query
from fastapi.testclient import TestClient
from pydantic import BaseModel, Field

app = FastAPI()

# =====================================================================================
# Without aliases


@app.get("/optional-list-str")
async def read_optional_list_str(
    p: Annotated[Optional[list[str]], Query()] = None,
):
    return {"p": p}

import pytest
from fastapi import FastAPI, Query
from fastapi.exceptions import FastAPIDeprecationWarning
from fastapi.testclient import TestClient

from .utils import needs_py310


def get_client():
    app = FastAPI()
    with pytest.warns(FastAPIDeprecationWarning):

        @app.get("/items/")
        async def read_items(
            q: Annotated[str | None, Query(regex="^fixedquery$")] = None,
        ):