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。
$year
Amazon DocumentDB 中的$year運算子會從日期或時間戳記擷取年份元件。
參數
範例 (MongoDB Shell)
下列範例示範如何使用 $year運算子從日期欄位中擷取年份元件。
建立範例文件
db.events.insertMany([
{ "_id": 1, "date": ISODate("2023-04-15T00:00:00Z") },
{ "_id": 3, "date": ISODate("2021-12-31T00:00:00Z") }
]);
查詢範例
db.events.aggregate([
{ $project: { year: { $year: "$date" } } }
]);
輸出
[
{ "_id": 1, "year": 2023 },
{ "_id": 3, "year": 2021 }
]
程式碼範例
若要檢視使用 $year命令的程式碼範例，請選擇您要使用的語言標籤：
- 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');
const result = await collection.aggregate([
{ $project: { year: { $year: "$date" } } }
]).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['events']
result = list(collection.aggregate([
{'$project': {'year': {'$year': '$date'}}}
]))
print(result)
client.close()
example()
