## ORMs

**FastAPI** works with any database and any style of library to talk to the database.

A common pattern is to use an "ORM": an "object-relational mapping" library.

An ORM has tools to convert ("*map*") between *objects* in code and database tables ("*relations*").

With an ORM, you normally create a class that represents a table in a SQL database, each attribute of the class represents a column, with a name and a type.

    {!> ../../../docs_src/security/tutorial001.py!}
    ```

!!! tip "Tipp"
    Hier bezieht sich `tokenUrl="token"` auf eine relative URL `token`, die wir noch nicht erstellt haben. Da es sich um eine relative URL handelt, entspricht sie `./token`.

                    <mxGeometry relative="1" as="geometry"/>
                </mxCell>
                <mxCell id="20" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;endArrow=none;endFill=0;strokeWidth=3;" parent="1" source="11" target="18" edge="1">
                    <mxGeometry relative="1" as="geometry"/>
                </mxCell>

                    <mxGeometry relative="1" as="geometry">
                        <Array as="points">
                            <mxPoint x="800" y="521"/>
                            <mxPoint x="800" y="560"/>
                        </Array>

                    <mxGeometry relative="1" as="geometry">
                        <Array as="points">
                            <mxPoint x="800" y="521"/>
                            <mxPoint x="800" y="560"/>
                        </Array>

from dirty_equals import IsOneOf
from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI(
    servers=[
        {"url": "/", "description": "Default, relative server"},
        {
            "url": "http://staging.localhost.tiangolo.com:8000",
            "description": "Staging but actually localhost still",
        },
        {"url": "https://prod.example.com"},
    ]
)


@app.get("/foo")
def foo():

Bunlara Pydantic üzerine kurulu <abbr title="Object-Relational Mapper">ORM</abbr> databaseler ve , <abbr title="Object-Document Mapper">ODM</abbr> kütüphaneler de dahil olmak üzere.

But every time we do:

```Python
Settings()
```

a new `Settings` object would be created, and at creation it would read the `.env` file again.

If the dependency function was just like:

```Python
def get_settings():
    return Settings()
```

# ~~SQL (Relational) Databases with Peewee~~ (deprecated)

!!! warning "Deprecated"
    This tutorial is deprecated and will be removed in a future version.

!!! warning
    If you are just starting, the tutorial [SQL (Relational) Databases](../tutorial/sql-databases.md){.internal-link target=_blank} that uses SQLAlchemy should be enough.

    Feel free to skip this.

## The normal process

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

As part of the application object creation, a *path operation* for `/openapi.json` (or for whatever you set your `openapi_url`) is registered.

It just returns a JSON response with the result of the application's `.openapi()` method.