$tsIncrement

8.0.1 版中的新增内容。

Amazon DocumentDB 中的$tsIncrement运算符将时间戳值的递增序数作为长整数返回。

参数

• expression：解析为时间戳的表达式。

示例（MongoDB Shell）

以下示例说明如何使用$tsIncrement运算符从时间戳值中提取序数增量。

创建示例文档

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

查询示例

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

输出

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

代码示例

要查看使用$tsIncrement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, 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()