Lowdefy
v3.17.2/Operators/_mql/

_mql

The _mql operator uses the mingo package to evaluate MongoDB query language statements as an operator.

Operator methods:

_mql.aggregate

({on: object[], pipeline: object[]}): object[]
([on: object[], pipeline: object[]]): object[]

The _mql.aggregate method runs a MongoDB aggregation pipeline on an input array.

Arguments

object
  • on: object[]: The data array on which to run the pipeline. It should be an array of objects.
  • pipeline: object[]: A MongoDB aggregation pipeline definition.

Examples

Transform request results:
_mql.aggregate:
  pipeline:
    - $match:
        age:
          $gte: 18
    - $addFields:
        averageScore:
          $avg:
            - $score1
            - $score2
  on:
    _request: my_request

_mql.expr

({on: object, expr: any}): any
([on: object, expr: any]): any

The _mql.expr method evaluates a MongoDB aggregation pipeline operator expression. This is any statement that could be written in a $project stage.

Arguments

object
  • on: object: An object to take as input for the expression.
  • expr: object: A MongoDB aggregation expression.

Examples

Calculate an average of three inputs:
_mql.aggregate:
  expr:
    $avg:
      - $input1
      - $input2
      - $input3
  on:
    _state: true

_mql.test

({on: object, test: object}): boolean
([on: object, test: object]): boolean

The _mql.test method tests if a object matches a MongoDB filter/query expression.

Arguments

object
  • on: object: The object to be tested.
  • test: object: A MongoDB filter/query expression.

Examples

Test if a number input is greater than 100:
_mql.test:
  test:
    number_input:
      $gte: 18
  on:
    number_input:
      _state: number_input