db.command.aggregate.isoWeek

1. Operator Description

Function: Returns the ISO 8601 week number (the week of the year) for a date field, which is an integer ranging from 1 to 53.

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

For example, January 7, 2016 is the first Thursday of that year, so the week from Monday, 2016.01.04 to Sunday, 2016.01.10 is week 1. Similarly, the week number for January 1, 2016 is 53.

2. Operator Parameters

Field	Type	Required	Description
-	Expression	Required	aggregate expression

3. Sample Code

Suppose the collection dates contains the following documents:

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

We use isoWeek() to project the date field and obtain the corresponding ISO 8601 week number (the week 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
const _ = db.command

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

The output is as follows:

{
  "isoWeek": 20
}