db.command.aggregate.dayOfWeek
1. Operator Description
Description: Returns the day of the week for a date field, which is an integer ranging from 1 (Sunday) to 7 (Saturday).
Declaration: db.command.aggregate.dayOfWeek(<date field>)
Notes: Sunday is the first day of the week.
2. Operator Parameters
Field | Type | Required | Description |
---|---|---|---|
- | Expression | Required | Date field |
3. Sample Code
Suppose the collection dates
contains the following documents:
{
"_id": 1,
"date": ISODate("2019-05-14T09:38:51.686Z")
}
We use dayOfWeek()
to project the date
field and obtain the corresponding day of the week:
// 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,
dayOfWeek: $.dayOfWeek('$date')
})
.end()
console.log(res.data)
}
The output is as follows:
{
"dayOfWeek": 3
}