@app.get("/decorator-depends/", dependencies=[Depends(common_parameters)])
async def decorator_depends():
    return {"in": "decorator-depends"}


@router.get("/router-depends/")
async def router_depends(commons: dict = Depends(common_parameters)):
    return {"in": "router-depends", "params": commons}


@router.get("/router-decorator-depends/", dependencies=[Depends(common_parameters)])
async def router_decorator_depends():

////

**FastAPI** 🤙 `CommonQueryParams` 🎓. 👉 ✍ "👐" 👈 🎓 & 👐 🔜 🚶‍♀️ 🔢 `commons` 👆 🔢.

## 🆎 ✍ 🆚 `Depends`

👀 ❔ 👥 ✍ `CommonQueryParams` 🕐 🔛 📟:

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

🏁 `CommonQueryParams`,:

```Python
... = Depends(CommonQueryParams)
```

...⚫️❔ **FastAPI** 🔜 🤙 ⚙️ 💭 ⚫️❔ 🔗.

@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate, session: Session = Depends(get_session)):
    db_hero = Hero.model_validate(hero)
    session.add(db_hero)
    session.commit()
    session.refresh(db_hero)
    return db_hero


@app.get("/heroes/", response_model=List[HeroPublic])
def read_heroes(
    session: Session = Depends(get_session),
    offset: int = 0,
    limit: int = Query(default=100, le=100),
):

@app.get("/async")
async def get_async(state: str = Depends(asyncgen_state)):
    return state


@app.get("/sync")
async def get_sync(state: str = Depends(generator_state)):
    return state


@app.get("/async_raise")
async def get_async_raise(state: str = Depends(asyncgen_state_try)):
    assert state == "asyncgen raise started"
    raise AsyncDependencyError()

    return user


async def get_current_active_user(
    current_user: Annotated[User, Depends(get_current_user)],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login(form_data: Annotated[OAuth2PasswordRequestForm, Depends()]):
    user_dict = fake_users_db.get(form_data.username)
    if not user_dict:

```Python
commons: Annotated[CommonQueryParams, Depends()]
```

////

//// tab | Python 3.6 без Annotated

/// tip | "Подсказка"

Рекомендуется использовать версию с `Annotated` если возможно.

///

```Python
commons: CommonQueryParams = Depends()
```

////

@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate, session: Session = Depends(get_session)):
    db_hero = Hero.model_validate(hero)
    session.add(db_hero)
    session.commit()
    session.refresh(db_hero)
    return db_hero


@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
    session: Session = Depends(get_session),
    offset: int = 0,
    limit: int = Query(default=100, le=100),
):

async def get_current_active_user(
    current_user: Annotated[User, Depends(get_current_user)],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:

```

////

**FastAPI** 调用 `CommonQueryParams` 类。这将创建该类的一个 "实例"，该实例将作为参数 `commons` 被传递给你的函数。

## 类型注解 vs `Depends`

注意，我们在上面的代码中编写了两次`CommonQueryParams`：

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

最后的 `CommonQueryParams`:

```Python
... = Depends(CommonQueryParams)
```

...实际上是 **Fastapi** 用来知道依赖项是什么的。

FastAPI 将从依赖项中提取声明的参数，这才是 FastAPI 实际调用的。

def on_startup():
    create_db_and_tables()


@app.post("/heroes/")
def create_hero(hero: Hero, session: Session = Depends(get_session)) -> Hero:
    session.add(hero)
    session.commit()
    session.refresh(hero)
    return hero


@app.get("/heroes/")
def read_heroes(
    session: Session = Depends(get_session),
    offset: int = 0,
    limit: int = Query(default=100, le=100),
) -> list[Hero]: