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# $tsIncrement
<a name="tsIncrement"></a>

8.0.1 版的新功能。

Amazon DocumentDB 中的`$tsIncrement`運算子會從時間戳記值傳回增量序數，做為長整數。

**參數**
+ `expression`：解析為時間戳記的表達式。

## 範例 (MongoDB Shell)
<a name="tsIncrement-examples"></a>

下列範例顯示如何使用 `$tsIncrement`運算子從時間戳記值中擷取序數增量。

**建立範例文件**

```
db.events.insertMany([
  {_id: 1, ts: Timestamp(1678900000, 1)},
  {_id: 2, ts: Timestamp(1678900000, 2)},
  {_id: 3, ts: Timestamp(1678900001, 1)}
]);
```

**查詢範例**

```
db.events.aggregate([
  { $project: { increment: { $tsIncrement: "$ts" } } }
]);
```

**輸出**

```
[
  {_id: 1, increment: Long("1")},
  {_id: 2, increment: Long("2")},
  {_id: 3, increment: Long("1")}
]
```

## 程式碼範例
<a name="tsIncrement-code"></a>

若要檢視使用 `$tsIncrement` 運算子的程式碼範例，請選擇您要使用的語言標籤：

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

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

async function example() {
  const client = new MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  try {
    await client.connect();
    const db = client.db('test');
    const collection = db.collection('events');
    const result = await collection.aggregate([
      { $project: { increment: { $tsIncrement: "$ts" } } }
    ]).toArray();
    console.log(result);
  } finally {
    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')
    try:
        db = client['test']
        collection = db['events']
        result = list(collection.aggregate([
            {'$project': {'increment': {'$tsIncrement': '$ts'}}}
        ]))
        print(result)
    finally:
        client.close()

example()
```

------