## Випадок використання { #use-case }

Почнемо з прикладу випадку використання, а потім подивимось, як це вирішити.

Уявімо, що у вас є моделі машинного навчання, якими ви хочете обробляти запити. 🤖

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"flag"
	"fmt"
	"go/build"
	"internal/testenv"
	"os"
	"path/filepath"
	"slices"
	"strings"
	"sync"
	"testing"
)

var flagCheck = flag.Bool("check", false, "run API checks")

func TestMain(m *testing.M) {
	flag.Parse()

/*
 * Copyright (C) 2014 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2014 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

# Bancos de Dados SQL (Relacionais) { #sql-relational-databases }

**FastAPI** não exige que você use um banco de dados SQL (relacional). Mas você pode usar **qualquer banco de dados** que quiser.

Aqui veremos um exemplo usando [SQLModel](https://sqlmodel.tiangolo.com/).

但当你使用 `Security` 而不是 `Depends` 时，**FastAPI** 会知道它可以声明安全作用域，在内部使用它们，并用 OpenAPI 文档化 API。

另外，从 `fastapi` 导入的 `Query`、`Path`、`Depends`、`Security` 等，实际上都是返回特殊类的函数。

///

## 使用 `SecurityScopes` { #use-securityscopes }

现在更新依赖项 `get_current_user`。

上面那些依赖会用到它。

这里我们使用之前创建的同一个 OAuth2 方案，并把它声明为依赖：`oauth2_scheme`。

因为这个依赖函数本身没有任何作用域需求，所以我们可以用 `Depends(oauth2_scheme)`，当不需要指定安全作用域时，不必使用 `Security`。

改用 `Security` 而不是 `Depends`，能讓 FastAPI 知道可以宣告安全性 scopes、在內部使用它們，並用 OpenAPI 文件化 API。

另外，當你從 `fastapi` 匯入 `Query`、`Path`、`Depends`、`Security` 等時，實際上它們是回傳特殊類別的函式。

///

## 使用 `SecurityScopes` { #use-securityscopes }

現在更新相依性 `get_current_user`。

上面的相依性就是使用它。

這裡我們使用先前建立的相同 OAuth2 scheme，並將其宣告為相依性：`oauth2_scheme`。

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,