firebase-js-sdk/docs-devsite/firestore_lite_pipelines.aggregatefunction.md

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AggregateFunction class

A class that represents an aggregate function.

Signature:

export declare class AggregateFunction 

Constructors

Constructor	Modifiers	Description
(constructor)(name, params)		Constructs a new instance of the AggregateFunction class

Properties

Property	Modifiers	Type	Description
exprType		ExpressionType

Methods

Method	Modifiers	Description
as(name)		Assigns an alias to this AggregateFunction. The alias specifies the name that the aggregated value will have in the output document.

AggregateFunction.(constructor)

Constructs a new instance of the AggregateFunction class

Signature:

constructor(name: string, params: Expression[]);

Parameters

Parameter	Type	Description
name	string
params	Expression[]

AggregateFunction.exprType

Signature:

exprType: ExpressionType;

AggregateFunction.as()

Assigns an alias to this AggregateFunction. The alias specifies the name that the aggregated value will have in the output document.

Signature:

as(name: string): AliasedAggregate;

Parameters

Parameter	Type	Description
name	string	The alias to assign to this AggregateFunction.

Returns:

AliasedAggregate

A new AliasedAggregate that wraps this AggregateFunction and associates it with the provided alias.

Example

// Calculate the average price of all items and assign it the alias "averagePrice".
firestore.pipeline().collection("items")
  .aggregate(field("price").average().as("averagePrice"));