本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

# \$1lte
<a name="lte-aggregation"></a>

`$lte`聚合运算符比较两个值，`true`如果第一个值小于或等于第二个值，则返回，否则返回`false`。

**参数**
+ `expression1`：要比较的第一个值。
+ `expression2`: 第二个要比较的值。

## 示例（MongoDB 外壳）
<a name="lte-aggregation-examples"></a>

以下示例演示如何使用`$lte`运算符来识别经济实惠的项目。

**创建示例文档**

```
db.menu.insertMany([
  { _id: 1, dish: "Salad", price: 8 },
  { _id: 2, dish: "Pasta", price: 12 },
  { _id: 3, dish: "Soup", price: 6 }
]);
```

**查询示例**

```
db.menu.aggregate([
  {
    $project: {
      dish: 1,
      price: 1,
      affordable: { $lte: ["$price", 10] }
    }
  }
]);
```

**输出**

```
[
  { _id: 1, dish: 'Salad', price: 8, affordable: true },
  { _id: 2, dish: 'Pasta', price: 12, affordable: false },
  { _id: 3, dish: 'Soup', price: 6, affordable: true }
]
```

## 代码示例
<a name="lte-aggregation-code"></a>

要查看使用`$lte`聚合运算符的代码示例，请选择要使用的语言的选项卡：

------
#### [ Node.js ]

```
const { MongoClient } = require('mongodb');

async function example() {
  const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  const db = client.db('test');
  const collection = db.collection('menu');

  const result = await collection.aggregate([
    {
      $project: {
        dish: 1,
        price: 1,
        affordable: { $lte: ["$price", 10] }
      }
    }
  ]).toArray();

  console.log(result);
  await client.close();
}

example();
```

------
#### [ Python ]

```
from pymongo import MongoClient

def example():
    client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
    db = client['test']
    collection = db['menu']

    result = list(collection.aggregate([
        {
            '$project': {
                'dish': 1,
                'price': 1,
                'affordable': { '$lte': ['$price', 10] }
            }
        }
    ]))

    print(result)
    client.close()

example()
```

------