SetStage class

$set aggregation stage

Stage description

Available since MongoDB version 4.2

Adds new fields to documents. $set outputs documents that contain all existing fields from the input documents and newly added fields.

The $set stage is an alias for $addFields.

$set appends new fields to existing documents. You can include one or more $set stages in an aggregation operation.

To add field or fields to embedded documents (including documents in arrays) use the dot notation.

To add an element to an existing array field with $set, use with $concatArrays (ConcatArrays).

Dart code:

SetStage({
  'totalHomework': Sum(Field('homework')),
  'totalQuiz': Sum(Field('quiz'))
}).build()

Equivalent mongoDB aggregation stage:

{
  $set: {
    totalHomework: { $sum: "$homework" },
    totalQuiz: { $sum: "$quiz" }
  }
}

https://docs.mongodb.com/manual/reference/operator/aggregation/set/

Inheritance

Constructors

SetStage(Map<String, dynamic> fields)
Creates $set aggregation stage

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

build() → Map<String, Object>
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited