And whenever you update the backend code, and **regenerate** the frontend, it would have any new *path operations* available as methods, the old ones removed, and any other change would be reflected on the generated code. 🤓

This also means that if something changed it will be **reflected** on the client code automatically. And if you **build** the client it will error out if you have any **mismatch** in the data used.

    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> dep: Raise other exception
    end
    Note over dep: After yield
    opt Handle other exception
        dep -->> dep: Handle exception, can't change response. E.g. close DB session.
    end
```

!!! info

* Create a `database` object.

```Python hl_lines="3  9  12"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! tip
    If you were connecting to a different database (e.g. PostgreSQL), you would need to change the `DATABASE_URL`.

## Create the tables

In this case, we are creating the tables in the same Python file, but in production, you would probably want to create them with Alembic, integrated with migrations, etc.

But, sadly, you get nothing useful:

<img src="/img/python-types/image01.png">

### Add types

Let's modify a single line from the previous version.

We will change exactly this fragment, the parameters of the function, from:

```Python
    first_name, last_name
```

to:

```Python
    first_name: str, last_name: str
```

That's it.

<img src="/img/tutorial/extending-openapi/image03.png">

## Change the Theme

The same way you could set the syntax highlighting theme with the key `"syntaxHighlight.theme"` (notice that it has a dot in the middle):

```Python hl_lines="3"
{!../../../docs_src/configure_swagger_ui/tutorial002.py!}
```

That configuration would change the syntax highlighting color theme:

After a week, the token will be expired and the user will not be authorized and will have to sign in again to get a new token. And if the user (or a third party) tried to modify the token to change the expiration, you would be able to discover it, because the signatures would not match.

These last **three consecutive releases** are independent so that you can **migrate gradually**:

* First to FastAPI `0.68.2`, with no breaking changes, but upgrading all the sub-dependencies.
* Next to FastAPI `0.69.0`, which upgrades Starlette to `0.15.0`, with AnyIO support, and a higher chance of having breaking changes in your code.

    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> dep: Raise other exception
    end
    Note over dep: After yield
    opt Handle other exception
        dep -->> dep: Handle exception, can't change response. E.g. close DB session.
    end
```

!!! info "情報"

 <span style="background-color:#C4A000"><font color="#2E3436">╰─────────────────────────────────────────────────────╯</font></span>

<font color="#4E9A06">INFO</font>:     Will watch for changes in these directories: [&apos;/home/user/code/awesomeapp&apos;]
<font color="#4E9A06">INFO</font>:     Uvicorn running on <b>http://127.0.0.1:8000</b> (Press CTRL+C to quit)

    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> dep: Raise other exception
    end
    Note over dep: After yield
    opt Handle other exception
        dep -->> dep: Handle exception, can't change response. E.g. close DB session.
    end
```

!!! info