该类的每个*实例对象都代表数据库中的一行数据。*

又例如，一个对象`orion_cat`（`Pet`的一个实例）可以有一个属性`orion_cat.type`, 对标数据库中的`type`列。并且该属性的值可以是其它，例如`"cat"`。

这些 ORM 还具有在表或实体之间建立关系的工具（比如创建多表关系）。

这样，您还可以拥有一个属性`orion_cat.owner`，它包含该宠物所有者的数据，这些数据取自另外一个表。

因此，`orion_cat.owner.name`可能是该宠物主人的姓名（来自表`owners`中的列`name`）。

它可能有一个像`"Arquilian"`(一种业务逻辑)。

当您尝试从您的宠物对象访问它时，ORM 将完成所有工作以从相应的表*所有者那里再获取信息。*

🖼 🎚 `orion_cat` (👐 `Pet`) 💪 ✔️ 🔢 `orion_cat.type`, 🏓 `type`. & 💲 👈 🔢 💪, ✅ `"cat"`.

👫 🐜 ✔️ 🧰 ⚒ 🔗 ⚖️ 🔗 🖖 🏓 ⚖️ 👨‍💼.

👉 🌌, 👆 💪 ✔️ 🔢 `orion_cat.owner` & 👨‍💼 🔜 🔌 💽 👉 🐶 👨‍💼, ✊ ⚪️➡️ 🏓 *👨‍💼*.

, `orion_cat.owner.name` 💪 📛 (⚪️➡️ `name` 🏓 `owners` 🏓) 👉 🐶 👨‍💼.

⚫️ 💪 ✔️ 💲 💖 `"Arquilian"`.

& 🐜 🔜 🌐 👷 🤚 ℹ ⚪️➡️ 🔗 🏓 *👨‍💼* 🕐❔ 👆 🔄 🔐 ⚫️ ⚪️➡️ 👆 🐶 🎚.

This way, you could also have an attribute `orion_cat.owner` and the owner would contain the data for this pet's owner, taken from the table *owners*.

So, `orion_cat.owner.name` could be the name (from the `name` column in the `owners` table) of this pet's owner.

It could have a value like `"Arquilian"`.

And the ORM will do all the work to get the information from the corresponding table *owners* when you try to access it from your pet object.

from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: Optional[float] = None
    owner_ids: Optional[List[int]] = None


@app.get("/items/invalid", response_model=Item)
def get_invalid():
    return {"name": "invalid", "price": "foo"}


@app.get("/items/invalidnone", response_model=Item)

from pydantic import BaseModel


class ItemBase(BaseModel):
    title: str
    description: str | None = None


class ItemCreate(ItemBase):
    pass


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

    return db.query(models.Item).offset(skip).limit(limit).all()


def create_user_item(db: Session, item: schemas.ItemCreate, user_id: int):
    db_item = models.Item(**item.dict(), owner_id=user_id)
    db.add(db_item)
    db.commit()
    db.refresh(db_item)

!!! note "Technical Details"
    Actually, `Query`, `Path` and others you'll see next create objects of subclasses of a common `Param` class, which is itself a subclass of Pydantic's `FieldInfo` class.

    And Pydantic's `Field` returns an instance of `FieldInfo` as well.

    `Body` also returns objects of a subclass of `FieldInfo` directly. And there are others you will see later that are subclasses of the `Body` class.

    tags: set[str] = set()
    images: list[Image] | None = None


class Offer(BaseModel):
    name: str
    description: str | None = None
    price: float
    items: list[Item]


@app.post("/offers/")
async def create_offer(offer: Offer):

...Burada isə sizə icmanı göstərmək istəyirəm.

---

**FastAPI** icmadan çoxlu dəstək alır və mən onların əməyini vurğulamaq istəyirəm.

Bu insanlar:

* [GitHub-da başqalarının suallarına kömək edirlər](help-fastapi.md#help-others-with-questions-in-github){.internal-link target=_blank}.
* [Pull Request-lər yaradırlar](help-fastapi.md#create-a-pull-request){.internal-link target=_blank}.

---

**FastAPI**, topluluğundan çok destek alıyor. Ben de onların katkılarını vurgulamak istiyorum.

Bu insanlar:

* [GitHubdaki soruları cevaplayarak diğerlerine yardım ediyor](help-fastapi.md#help-others-with-questions-in-github){.internal-link target=_blank}.
* [Pull Request'ler oluşturuyor](help-fastapi.md#create-a-pull-request){.internal-link target=_blank}.