db.command.aggregate.setEquals

1. Operator Description

Function: Takes two sets as input and determines whether they contain identical elements (ignoring order and duplicates).

Declaration: setEquals([expression1, expression2])

2. Operator Parameters

Field	Type	Required	Description
-	<Array>Expression	Required	array of aggregate expressions

3. Sample Code

Suppose the collection test contains the following data:

{ "_id": 1, "A": [ 1, 2 ], "B": [ 1, 2 ] }
{ "_id": 2, "A": [ 1, 2 ], "B": [ 2, 1, 2 ] }
{ "_id": 3, "A": [ 1, 2 ], "B": [ 1, 2, 3 ] }
{ "_id": 4, "A": [ 1, 2 ], "B": [ 3, 1 ] }
{ "_id": 5, "A": [ 1, 2 ], "B": [ ] }
{ "_id": 6, "A": [ 1, 2 ], "B": [ {}, [] ] }
{ "_id": 7, "A": [ ], "B": [ ] }
{ "_id": 8, "A": [ ], "B": [ 1 ] }

The following code uses setEquals to determine whether two sets contain identical elements:

// 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('test')
    .aggregate()
    .project({
      sameElements: $.setEquals(['$A', '$B'])
    })
    .end()
  console.log(res.data)
}

{ "_id": 1, "sameElements": true }
{ "_id": 2, "sameElements": true }
{ "_id": 3, "sameElements": false }
{ "_id": 4, "sameElements": false }
{ "_id": 5, "sameElements": false }
{ "_id": 6, "sameElements": false }
{ "_id": 7, "sameElements": true }
{ "_id": 8, "sameElements": false }