### Providing the `root_path` { #providing-the-root-path }

To achieve this, you can use the command line option `--root-path` like:

<div class="termy">

```console
$ fastapi run main.py --forwarded-allow-ips="*" --root-path /api/v1

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

```bash
# 向宇宙輸出問候
echo "Hello universe"
```

...以及一個主控台範例...

```console
$ <font color="#4E9A06">fastapi</font> run <u style="text-decoration-style:solid">main.py</u>
<span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting server
        Searching for package file structure
```

...以及另一個主控台範例...

```console
// 建立目錄 "Code"
$ mkdir code
// 切換到該目錄
$ cd code
```

接下来，运行服务器，并把配置作为环境变量传入，例如你可以设置 `ADMIN_EMAIL` 和 `APP_NAME`：

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" fastapi run main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip | 提示

要为单个命令设置多个环境变量，只需用空格分隔它们，并把它们都放在命令前面。

///

We can **read** `Hero`s from the database using a `select()`. We can include a `limit` and `offset` to paginate the results.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[48:55] hl[51:52,54] *}

### Read One Hero { #read-one-hero }

We can **read** a single `Hero`.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[58:63] hl[60] *}

### Delete a Hero { #delete-a-hero }

Then you could disable OpenAPI (including the UI docs) by setting the environment variable `OPENAPI_URL` to the empty string, like:

<div class="termy">

```console
$ OPENAPI_URL= uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

Then if you go to the URLs at `/openapi.json`, `/docs`, or `/redoc` you will just get a `404 Not Found` error like:

      if (rangeMap.asMapOfRanges().isEmpty()) {
        return;
      }
      Range<K> span = rangeMap.span();
      checkArgument(
          subRange.encloses(span),
          "Cannot putAll rangeMap with span %s into a subRangeMap(%s)",
          span,
          subRange);
      TreeRangeMap.this.putAll(rangeMap);
    }

    @Override
    public void clear() {

  @Override
  public ImmutableRangeSet<C> subRangeSet(Range<C> range) {
    if (!isEmpty()) {
      Range<C> span = span();
      if (range.encloses(span)) {
        return this;
      } else if (range.isConnected(span)) {
        return new ImmutableRangeSet<>(intersectRanges(range));
      }
    }
    return of();
  }

  /**

///

## Check the automatic API docs { #check-the-automatic-api-docs }

Now, run your app:

<div class="termy">

```console
$ fastapi dev

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

And open the docs at [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs).

 * MutableValueGraph<String, Double> graph =
 *     ValueGraphBuilder.undirected().allowsSelfLoops(true).build();
 * graph.putEdgeValue("San Francisco", "San Francisco", 0.0);
 * graph.putEdgeValue("San Jose", "San Jose", 0.0);
 * graph.putEdgeValue("San Francisco", "San Jose", 48.4);
 *
 * // Building an immutable value graph
 * ImmutableValueGraph<String, Double> immutableGraph =
 *     ValueGraphBuilder.undirected()

                    <span class="btn btn-info" role="button">Update baseline</span>
                  </summary>
                  <div class="well">
                    Sometimes, the change was made on the `release` branch but hasn't yet been published to the baseline version.