db.command.aggregate.toUpper

1. Operator Description

Function: Converts a string to uppercase and returns it.

Declaration: db.command.aggregate.toUpper(<expression>)

2. Operator Parameters

Field	Type	Required	Description
-	Expression	Required	As long as an expression can be parsed into a string, it is a valid expression. For example: $ + specified field.

3. Sample Code

Suppose the collection students contains the following records:

{ "firstName": "Yuanxin", "group": "a", "lastName": "Dong", "score": 84 }
{ "firstName": "Weijia", "group": "a", "lastName": "Wang", "score": 96 }
{ "firstName": "Chengxi", "group": "b", "lastName": "Li", "score": 80 }

Use toUpper to convert the value of the lastName field to uppercase:

// 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('students')
    .aggregate()
    .project({
      _id: 0,
      result: $.toUpper('$lastName')
    })
    .end()
  console.log(res.data)
}

The returned result is as follows:

{ "result": "DONG" }
{ "result": "WANG" }
{ "result": "LI" }