$set 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.

Both stages are equivalent to a $project stage that explicitly specifies all existing fields in the input documents and adds the new fields.

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:

$set([
  fieldSum('totalHomework', Field('homework')),
  fieldSum('totalQuiz', r'$quiz')
]).build()

or

$set.raw({
  ...FieldExpression('totalHomework', $sum(Field('homework'))).build(),
  'totalQuiz': $sum(r'$quiz')
}).build()

Equivalent mongoDB aggregation stage:

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

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

Inheritance

Constructors

$set(List<FieldExpression<ExpressionContent>> expressions)
Creates $set aggregation stage
$set.raw(MongoDocument raw)

Properties

content → ExpressionContent
no setterinherited
entry ↔ MapEntry<String, ExpressionContent>
getter/setter pairinherited
fieldName → String
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
key → String
no setterinherited
rawContent → dynamic
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
stageName → String
no setterinherited

Methods

build() → MongoDocument
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