本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。
$tsIncrement
8.0.1 版的新功能。
Amazon DocumentDB 中的$tsIncrement運算子會從時間戳記值傳回增量序數，做為長整數。
參數
範例 (MongoDB Shell)
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
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()
