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db.command.aggregate.dayOfYear

1. Operator Description

Function: Returns the day of the year for a date field, which is an integer between 1 and 366.

Declaration: db.command.aggregate.dayOfYear(<date field>)

2. Operator Parameters

FieldTypeRequiredDescription
-ExpressionRequiredDate field

3. Sample Code

Suppose the collection dates contains the following documents:

{
"_id": 1,
"date": ISODate("2019-05-14T09:38:51.686Z")
}

We use dayOfYear() to project the date field and obtain the corresponding day of the year:

// Sample code in the Cloud Function environment
const tcb = require('@cloudbase/node-sdk')
const app = tcb.init({
env: 'xxx'
})

const db = app.database()
const $ = db.command.aggregate

exports.main = async (event, context) => {
const res = await db
.collection('dates')
.aggregate()
.project({
_id: 0,
dayOfYear: $.dayOfYear('$date')
})
.end()
console.log(res.data)
}

The output is as follows:

{
"dayOfYear": 134
}