您可以在[Project Generation - Template](https://fastapi.tiangolo.com/zh/project-generation/)的模板中找到一个 FastAPI 项目中的 Alembic 示例。具体在[`alembic`代码目录中](https://github.com/tiangolo/full-stack-fastapi-postgresql/tree/master/src/backend/app/alembic/)。

### 创建依赖项

现在使用我们在`sql_app/database.py`文件中创建的`SessionLocal`来创建依赖项。

我们需要每个请求有一个独立的数据库会话/连接（`SessionLocal`），在所有请求中使用相同的会话，然后在请求完成后关闭它。

然后将为下一个请求创建一个新会话。

    response.headers["x-level0"] = "True"


async def dep1(response: Response):
    response.headers["x-level1"] = "True"


async def dep2(response: Response):
    response.headers["x-level2"] = "True"


async def dep3(response: Response):
    response.headers["x-level3"] = "True"


async def dep4(response: Response):
    response.headers["x-level4"] = "True"


async def dep5(response: Response):

      - name: Setup tmate session
        uses: mxschmitt/action-tmate@v3
        if: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.debug_enabled == 'true' }}
        with:
          limit-access-to-actor: true
      - uses: docker://tiangolo/latest-changes:0.3.0
      # - uses: tiangolo/latest-changes@main
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

                        {
                            "required": True,
                            "schema": {"title": "Username", "type": "string"},
                            "name": "username",
                            "in": "path",
                        },
                        {
                            "required": True,
                            "schema": {"title": "Token", "type": "string"},

                        {
                            "required": True,
                            "schema": {"title": "Username", "type": "string"},
                            "name": "username",
                            "in": "path",
                        },
                        {
                            "required": True,
                            "schema": {"title": "Token", "type": "string"},

class Item(ItemBase):
    id: int
    owner_id: int

    class Config:
        orm_mode = True


class UserBase(BaseModel):
    email: str


class UserCreate(UserBase):
    password: str


class User(UserBase):
    id: int
    is_active: bool
    items: list[Item] = []

    class Config:

                    "summary": "Read Item",
                    "operationId": "read_item_items__item_id__get",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "string"},
                            "name": "item_id",
                            "in": "path",
                        }
                    ],

👆 💪 🔎 🖼 ⚗ FastAPI 🏗 📄 ⚪️➡️ [🏗 ⚡ - 📄](../project-generation.md){.internal-link target=_blank}. 🎯 <a href="https://github.com/tiangolo/full-stack-fastapi-postgresql/tree/master/src/backend/app/alembic/" class="external-link" target="_blank"> `alembic` 📁 ℹ 📟</a>.

### ✍ 🔗

🔜 ⚙️ `SessionLocal` 🎓 👥 ✍ `sql_app/database.py` 📁 ✍ 🔗.

        deprecated: Union[deprecated, str, bool, None] = None,
        include_in_schema: bool = True,
        json_schema_extra: Union[Dict[str, Any], None] = None,
        **extra: Any,
    ):
        super().__init__(
            default=default,
            default_factory=default_factory,
            annotation=annotation,
            embed=True,
            media_type=media_type,
            alias=alias,

                        {
                            "required": True,
                            "schema": {"title": "X-Token", "type": "string"},
                            "name": "x-token",
                            "in": "header",
                        },
                        {
                            "required": True,
                            "schema": {"title": "X-Key", "type": "string"},