# $gt

**$gt**

*语法*：`{field: {$gt: value} }`

`$gt`选择的值`field`大于（即`>`）指定的那些文档 `value`。

对于大多数数据类型，比较运算符仅对BSON类型与查询值的类型匹配的字段执行比较 。MongoDB通过Type Bracketing支持有限的跨BSON比较。

考虑以下示例：

```
db.inventory.find( { qty: { $gt: 20 } } )
```

此查询将选择`inventory`集合中`qty`字段值大于`20`的所有文档。

考虑以下示例，该示例将`$gt`运算符与嵌入式文档中的字段一起使用：

```
db.inventory.update( { "carrier.fee": { $gt: 2 } }, { $set: { price: 9.99 } } )
```

`update()`操作将设置`price`找到的第一个文档中包含嵌入文档`carrier`的`fee`字段的值，该嵌入文档的字段值大于`2`。

要`price`在包含嵌入文档的\_所有\_文档中设置该字段的值，该嵌入文档`carrier`的`fee`字段值大于`2`，请在`update()`方法中指定`multi:true`选项：

```
db.inventory.update(
   { "carrier.fee": { $gt: 2 } },
   { $set: { price: 9.99 } },
   { multi: true }
)
```

> **也可以看看**
>
> `find()`，`update()`，`$set`。

译者：李冠飞

校对：


---

# 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/comparison-query-operators/gt.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.