db.command.aggregate.not

1. Operator Description

Function: Given an expression, if the expression returns true, then not returns false, otherwise returns true.

Declaration: db.command.aggregate.not(expression)

2. Operator Parameters

Field	Type	Required	Description
-	Expression	Yes	If the expression returns false, null, 0, or undefined, it resolves to false; otherwise, all other return values are considered true.

3. Sample Code

Suppose the collection price contains the following records:

{ "_id": 1, "min": 10, "max": 100 }
{ "_id": 2, "min": 60, "max": 80 }
{ "_id": 3, "min": 30, "max": 50 }

Find records where min is not greater than 40.

// 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('price')
    .aggregate()
    .project({
      fullfilled: $.not($.gt(['$min', 40]))
    })
    .end()
  console.log(res.data)
}

The returned result is as follows:

{ "_id": 1, "fullfilled": true }
{ "_id": 2, "fullfilled": false }
{ "_id": 3, "fullfilled": true }