t.Fatalf("failed to preload and find users: %v", err)
	}

	AssertEqual(t, result, users)
	AssertEqual(t, len(query), 2) // Check preload queries are merged

	if !regexp.MustCompile(`SELECT \* FROM .*tools.* WHERE .*IN.*`).MatchString(query[0]) {
		t.Fatalf("Expected first query to preload manager tools, got: %s", query[0])
	}
}

func TestNestedPreloadWithPointerJoin(t *testing.T) {
	type (
		Preload struct {

## 定义 `Form` 参数

创建表单（`Form`）参数的方式与 `Body` 和 `Query` 一样：

{* ../../docs_src/request_forms/tutorial001.py hl[7] *}

例如，OAuth2 规范的 "密码流" 模式规定要通过表单字段发送 `username` 和 `password`。

<abbr title="specification">该规范</abbr>要求字段必须命名为 `username` 和 `password`，并通过表单字段发送，不能用 JSON。

使用 `Form` 可以声明与 `Body` （及 `Query`、`Path`、`Cookie`）相同的元数据和验证。

/// info | 说明

`Form` 是直接继承自 `Body` 的类。

///

from typing import Annotated, Union

from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select


class HeroBase(SQLModel):
    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)


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


class HeroPublic(HeroBase):

    response = client.get("/items/42")
    assert response.status_code == 422, response.text
    assert response.json() == {
        "detail": [
            {
                "loc": ["query", "q"],
                "input": None,
                "msg": "Field required",
                "type": "missing",
            }
        ]
    }


def test_openapi_schema(client: TestClient):

{* ../../docs_src/schema_extra_example/tutorial002_py310.py hl[2,8:11] *}

## `examples` в JSON Schema — OpenAPI { #examples-in-json-schema-openapi }

При использовании любой из функций:

* `Path()`
* `Query()`
* `Header()`
* `Cookie()`
* `Body()`
* `Form()`
* `File()`

вы также можете объявить набор `examples` с дополнительной информацией, которая будет добавлена в их **JSON Schema** внутри **OpenAPI**.

And it can return anything you want.

In this case, this dependency expects:

* An optional query parameter `q` that is a `str`.
* An optional query parameter `skip` that is an `int`, and by default is `0`.
* An optional query parameter `limit` that is an `int`, and by default is `100`.

And then it just returns a `dict` containing those values.

/// info

`Form` sınıfını `fastapi`'den projenize dahil edin:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[3] *}

## `Form` Parametrelerini Tanımlayın

Form parametrelerini `Body` veya `Query` için yaptığınız gibi oluşturun:

{* ../../docs_src/request_forms/tutorial001_an_py39.py hl[9] *}

    response = client.get("/items/42")
    assert response.status_code == 422, response.text
    assert response.json() == {
        "detail": [
            {
                "loc": ["query", "q"],
                "input": None,
                "msg": "Field required",
                "type": "missing",
            }
        ]
    }


def test_openapi_schema(client: TestClient):

    response = client.get("/items/42")
    assert response.status_code == 422, response.text
    assert response.json() == {
        "detail": [
            {
                "loc": ["query", "q"],
                "input": None,
                "msg": "Field required",
                "type": "missing",
            }
        ]
    }


def test_openapi_schema(client: TestClient):

Tendrá una *path operation* que recibirá un cuerpo `Invoice`, y un parámetro de query `callback_url` que contendrá la URL para el callback.

Esta parte es bastante normal, probablemente ya estés familiarizado con la mayor parte del código:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip | Consejo