# 存在

如果确实想检查一下文档是否存在，你可以试用`HEAD`来替代`GET`方法，这样就是会返回HTTP头文件：

```javascript
curl -i -XHEAD /website/blog/123
```

如果文档存在，Elasticsearch将会返回`200 OK`的状态码：

```javascript
HTTP/1.1 200 OK
Content-Type: text/plain; charset=UTF-8
Content-Length: 0
```

如果不存在将会返回`404 Not Found`状态码：

```javascript
curl -i -XHEAD /website/blog/124
```

```javascript
HTTP/1.1 404 Not Found
Content-Type: text/plain; charset=UTF-8
Content-Length: 0
```

当然，这个反馈只代表了你查询的那一刻文档不存在，但是不代表几毫秒后它不存在，很可能与此同时，另一个进程正在创建文档。


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://hezhiqiang.gitbook.io/elasticsearch/data/exists.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.