# 元素查询运算符

> **注意**
>
> 有关特定运算符的详细信息，包括语法和示例，请单击特定运算符以转到其参考页。

| 名称                                                                                          | 描述               |
| ------------------------------------------------------------------------------------------- | ---------------- |
| [`$exists`](/can-kao/yun-suan-fu/query-and-projection-operators/element-query-operators.md) | 匹配具有指定字段的文档。     |
| [`$type`](/can-kao/yun-suan-fu/query-and-projection-operators/element-query-operators.md)   | 如果字段是指定类型，则选择文档。 |

译者：李冠飞

校对：


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# 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://docs.mongoing.com/can-kao/yun-suan-fu/query-and-projection-operators/element-query-operators.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.