# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

     * occurs an <code>SmbException</code> will be thrown. If the credentials are
     * valid, the method will return without throwing an exception. See the
     * last <a href="../../../faq.html">FAQ</a> question.
     * <p>
     * See also the <code>jcifs.smb1.smb1.client.logonShare</code> property.
     *
     * @param dc the domain controller to authenticate against

This can be very useful for setting up **resources** that you need to use for the whole app, and that are **shared** among requests, and/or that you need to **clean up** afterwards. For example, a database connection pool, or loading a shared machine learning model.

## Use Case { #use-case }

Let's start with an example **use case** and then see how to solve it with this.

```

////

So, when you need to declare a value as required while using `Query`, you can simply not declare a default value:

{* ../../docs_src/query_params_str_validations/tutorial006_an_py39.py hl[9] *}

### Required, can be `None` { #required-can-be-none }

You can declare that a parameter can accept `None`, but that it's still required. This would force clients to send a value, even if the value is `None`.

                }
                file.send(reqx, rspx);
                fp += rspx.count;
                len -= rspx.count;
                off += rspx.count;
            } else {
                req.setParam(file.fid, fp, len - w, b, off, w);
                fp += rsp.count;
                len -= rsp.count;
                off += rsp.count;
                file.send(req, rsp);
            }

            message.setFlags(request.getFlags());
            message.setTimeout((int) (context.getConfig().getWitnessRegistrationTimeout() / 1000));

            // Send the RPC request
            rpcHandle.sendrecv(message);

            // Create response from RPC message results
            WitnessRegisterResponse response = new WitnessRegisterResponse();

  ) : SocketEffect

  /**
   * On HTTP/2, send a [GOAWAY frame](https://tools.ietf.org/html/rfc7540#section-6.8) immediately
   * after the response and will close the connection when the client's socket is exhausted.
   *
   * On HTTP/1 this closes the socket.
   */
  public object ShutdownConnection : SocketEffect

  /**
   * On HTTP/2 this will send the error code on the stream.
   *

                req.setMaxOutputResponse(16);
                req.setFlags(Smb2IoctlRequest.SMB2_O_IOCTL_IS_FSCTL);
                final Smb2IoctlResponse resp = th.send(req, RequestParam.NO_RETRY);
                return ((SrvPipePeekResponse) resp.getOutputData()).getReadDataAvailable();
            }

```

...to:

```Python
        ... "item_price": item.price ...
```

...and see how your editor will auto-complete the attributes and know their types:

![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png)

For a more complete example including more features, see the <a href="https://fastapi.tiangolo.com/tutorial/">Tutorial - User Guide</a>.

- Temporary credentials do not need to be stored with the application but are generated dynamically and provided to the application when requested. When (or even before) the temporary credentials expire, the application can request new credentials.

Following are advantages for using temporary credentials:

- Eliminates the need to embed long-term credentials with an application.