SetWindowFields class

$setWindowFields aggregation stage

Stage description

Available since MongoDB version 5.0

Performs operations on a specified span of documents in a collection, known as a window, and returns the results based on the chosen window operator.

For example, you can use the $setWindowFields stage to output the:

• Difference in sales between two documents in a collection.
• Sales rankings.
• Cumulative sales totals.
• Analysis of complex time series information without exporting the data to an external database.

Example:

Dart code:

  SetWindowFields(
     partitionBy: {r'$year': r"$orderDate"},
     sortBy: {'orderDate': 1},
     output: Output('cumulativeQuantityForYear', Sum(r'$quantity'),
         documents: ["unbounded", "current"])).build(),

Equivalent mongoDB aggregation stage:

 {
   r'$setWindowFields': {
     'partitionBy': {r'$year': r"$orderDate"},
     'sortBy': {'orderDate': 1},
     'output': {
       'cumulativeQuantityForYear': {
         r'$sum': r"$quantity",
         'window': {
           'documents': ["unbounded", "current"]
         }
       }
     }
   }
 }

https://www.mongodb.com/docs/manual/reference/operator/aggregation/setWindowFields/

Inheritance

• Object
• AggregationStage
• SetWindowFields

Constructors

SetWindowFields({dynamic partitionBy, Map<String, int>? sortBy, dynamic defaultId, required dynamic output})

Creates $setWindowFields aggregation stage

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

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