# Query Parameters { #query-parameters }

When you declare other function parameters that are not part of the path parameters, they are automatically interpreted as "query" parameters.

{* ../../docs_src/query_params/tutorial001.py hl[9] *}

The query is the set of key-value pairs that go after the `?` in a URL, separated by `&` characters.

For example, in the URL:

```
http://127.0.0.1:8000/items/?skip=0&limit=10
```

        assertEquals("test (query1 OR query2)",
                getQuery("", new String[] { "test", "query1 OR query2" }, Collections.emptyMap(), Collections.emptyMap(), false));
        assertEquals("(test || extra)",
                getQuery("", new String[] { "test || extra" }, Collections.emptyMap(), Collections.emptyMap(), false));
        assertEquals("query1 query2",

# Query Parameter Models { #query-parameter-models }

If you have a group of **query parameters** that are related, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

{* ../../docs_src/query_param_models/tutorial001_an_py310.py hl[9:13,17] *}

**FastAPI** **extraerá** los datos para **cada campo** de los **parámetros query** en el request y te proporcionará el modelo de Pydantic que definiste.

## Revisa la Documentación

Puedes ver los parámetros query en la UI de documentación en `/docs`:

        facetQueryView.addQuery("key1", "query1");
        assertEquals(1, facetQueryView.getQueryMap().size());
        assertEquals("query1", facetQueryView.getQueryMap().get("key1"));

        facetQueryView.addQuery("key2", "query2");
        assertEquals(2, facetQueryView.getQueryMap().size());
        assertEquals("query2", facetQueryView.getQueryMap().get("key2"));

```
http://127.0.0.1:8000/items/foo-item
```

...필수 매개변수 `needy`를 넣지 않았기 때문에 아래와 같은 오류를 보게 됩니다:

```JSON
{
    "detail": [
        {
            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",
            "type": "value_error.missing"
        }
    ]
}
```

`needy`는 필수 매개변수이므로 URL에 반드시 설정해줘야 합니다:

    }

    @Test
    public void searchTestWithBoost() throws Exception {
        String field = "content";
        String query1 = "java";
        String query2 = "sample";
        Map<String, String> params = new HashMap<>();
        params.put("q", field + ":" + query1 + "^1000 OR " + field + ":" + query2);
        params.put("num", "100");

http://127.0.0.1:8000/items/foo-item
```

... sem adicionar o parâmetro obrigatório `needy`, você verá um erro como:

```JSON
{
    "detail": [
        {
            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",
            "type": "value_error.missing"
        }
    ]
}
```

Але тепер, додавши `Query(max_length=50)` всередину `Annotated`, ми повідомляємо FastAPI, що хочемо **додаткову валідацію** для цього значення — воно має містити максимум 50 символів. 😎

/// tip | Підказка

Ми використовуємо `Query()`, оскільки це **query параметр**. Далі ми розглянемо інші варіанти, як-от `Path()`, `Body()`, `Header()` та `Cookie()`, які приймають ті самі аргументи, що й `Query()`.

///

Тепер FastAPI:

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

This will validate the data, show a clear error when the data is not valid, and document the parameter in the OpenAPI schema *path operation*.

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

Keep in mind that when using `Query` inside of `Annotated` you cannot use the `default` parameter for `Query`.