app = FastAPI()


user_router = APIRouter()
item_router = APIRouter()


@user_router.get("/")
def get_users():
    return [{"user_id": "u1"}, {"user_id": "u2"}]


@user_router.get("/{user_id}")
def get_user(user_id: str):
    return {"user_id": user_id}


@item_router.get("/")
def get_items(user_id: Optional[str] = None):
    if user_id is None:

    assert "id" in data
    response = client.post("/users/", json=test_user)
    assert response.status_code == 400, response.text


@needs_py39
# TODO: pv2 add version with Pydantic v2
@needs_pydanticv1
def test_get_user(client):
    response = client.get("/users/1")
    assert response.status_code == 200, response.text
    data = response.json()
    assert "email" in data
    assert "id" in data


@needs_py39

    response = client.post("/users/", json=test_user)
    assert response.status_code == 400, response.text


@needs_py310
# TODO: pv2 add version with Pydantic v2
@needs_pydanticv1
def test_get_user(client):
    response = client.get("/users/1")
    assert response.status_code == 200, response.text
    data = response.json()
    assert "email" in data
    assert "id" in data


@needs_py310

    assert "id" in data
    response = client.post("/users/", json=test_user)
    assert response.status_code == 400, response.text


@needs_py39
# TODO: pv2 add version with Pydantic v2
@needs_pydanticv1
def test_get_user(client):
    response = client.get("/users/1")
    assert response.status_code == 200, response.text
    data = response.json()
    assert "email" in data
    assert "id" in data


@needs_py39

    assert "id" in data
    response = client.post("/users/", json=test_user)
    assert response.status_code == 400, response.text


# TODO: pv2 add version with Pydantic v2
@needs_pydanticv1
def test_get_user(client):
    response = client.get("/users/1")
    assert response.status_code == 200, response.text
    data = response.json()
    assert "email" in data
    assert "id" in data

    response = client.post("/users/", json=test_user)
    assert response.status_code == 400, response.text


@needs_py310
# TODO: pv2 add version with Pydantic v2
@needs_pydanticv1
def test_get_user(client):
    response = client.get("/users/1")
    assert response.status_code == 200, response.text
    data = response.json()
    assert "email" in data
    assert "id" in data


@needs_py310

    assert "id" in data
    response = client.post("/users/", json=test_user)
    assert response.status_code == 400, response.text


# TODO: pv2 add version with Pydantic v2
@needs_pydanticv1
def test_get_user(client):
    response = client.get("/users/1")
    assert response.status_code == 200, response.text
    data = response.json()
    assert "email" in data
    assert "id" in data

And then we can create the required dependency in the *path operation function*, to get that session directly.

With that, we can just call `crud.get_user` directly from inside of the *path operation function* and use that session.

!!! tip
    Notice that the values you return are SQLAlchemy models, or lists of SQLAlchemy models.

    {!> ../../../docs_src/sql_databases/sql_app/main.py!}
    ```

我们在依赖项中的每个请求之前利用`yield`创建数据库会话，然后关闭它。

所以我们就可以在*路径操作函数*中创建需要的依赖，就能直接获取会话。

这样，我们就可以直接从*路径操作函数*内部调用`crud.get_user`并使用该会话，来进行对数据库操作。

!!! tip
    请注意，您返回的值是 SQLAlchemy 模型或 SQLAlchemy 模型列表。

    但是由于所有路径操作的response_model都使用 Pydantic模型/使用orm_mode模式，因此您的 Pydantic 模型中声明的数据将从它们中提取并返回给客户端，并进行所有正常的过滤和验证。

!!! tip

    {!> ../../../docs_src/sql_databases/sql_app_py39/main.py!}
    ```

👥 🏗 💽 🎉 ⏭ 🔠 📨 🔗 ⏮️ `yield`, & ⤴️ 📪 ⚫️ ⏮️.

& ⤴️ 👥 💪 ✍ 🚚 🔗 *➡ 🛠️ 🔢*, 🤚 👈 🎉 🔗.

⏮️ 👈, 👥 💪 🤙 `crud.get_user` 🔗 ⚪️➡️ 🔘 *➡ 🛠️ 🔢* & ⚙️ 👈 🎉.

!!! tip
    👀 👈 💲 👆 📨 🇸🇲 🏷, ⚖️ 📇 🇸🇲 🏷.