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# \$1minute
<a name="minute"></a>

Amazon DocumentDB 中的`$minute`聚合管道阶段从日期或时间戳字段中提取分钟值。

当您需要在聚合管道中执行基于日期和时间的计算或分组时，此运算符很有用。

**参数**
+ `expression`：要从中提取分钟值的日期或时间戳字段。

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

以下示例演示如何使用`$minute`运算符按从时间戳字段中提取的分钟值对文档进行分组，并计算每组中的文档数量。

**创建示例文档**

```
db.events.insertMany([
  { timestamp: new Date("2023-04-15T10:30:25.000Z") },
  { timestamp: new Date("2023-04-15T10:30:35.000Z") },
  { timestamp: new Date("2023-04-15T10:31:05.000Z") },
  { timestamp: new Date("2023-04-15T10:31:45.000Z") },
  { timestamp: new Date("2023-04-15T10:32:15.000Z") }
]);
```

**查询示例**

```
db.events.aggregate([
  {
    $group: {
      _id: {
        minute: { $minute: "$timestamp" }
      },
      count: { $count: {} }
    }
  },
  { $sort: { "_id.minute": 1 } }
]);
```

**输出**

```
[
  { "_id": { "minute": 30 }, "count": 2 },
  { "_id": { "minute": 31 }, "count": 2 },
  { "_id": { "minute": 32 }, "count": 1 }
]
```

## 代码示例
<a name="minute-code"></a>

要查看使用该`$minute`命令的代码示例，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('events');

  await collection.insertMany([
    { timestamp: new Date("2023-04-15T10:30:25.000Z") },
    { timestamp: new Date("2023-04-15T10:30:35.000Z") },
    { timestamp: new Date("2023-04-15T10:31:05.000Z") },
    { timestamp: new Date("2023-04-15T10:31:45.000Z") },
    { timestamp: new Date("2023-04-15T10:32:15.000Z") }
  ]);

  const result = await collection.aggregate([
    {
      $group: {
        _id: {
          minute: { $minute: "$timestamp" }
        },
        count: { $count: {} }
      }
    },
    { $sort: { "_id.minute": 1 } }
  ]).toArray();

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

example();
```

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

```
from pymongo import MongoClient
from datetime import datetime

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['events']

    collection.insert_many([
        {'timestamp': datetime(2023, 4, 15, 10, 30, 25)},
        {'timestamp': datetime(2023, 4, 15, 10, 30, 35)},
        {'timestamp': datetime(2023, 4, 15, 10, 31, 5)},
        {'timestamp': datetime(2023, 4, 15, 10, 31, 45)},
        {'timestamp': datetime(2023, 4, 15, 10, 32, 15)}
    ])

    result = list(collection.aggregate([
        {
            '$group': {
                '_id': {
                    'minute': {'$minute': '$timestamp'}
                },
                'count': {'$count': {}}
            }
        },
        {'$sort': {'_id.minute': 1}}
    ]))

    print(result)
    client.close()

example()
```

------