AggregateFunction

class AggregateFunction

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A class that represents an aggregate function.

Summary

Public companion functions
AggregateFunction	arrayAgg(expression: Expression) Creates an aggregation that collects all values of an expression across multiple stage inputs into an array.
AggregateFunction	arrayAgg(fieldName: String) Creates an aggregation that collects all values of a field across multiple stage inputs into an array.
AggregateFunction	arrayAggDistinct(expression: Expression) Creates an aggregation that collects all distinct values of an expression across multiple stage inputs into an array.
AggregateFunction	arrayAggDistinct(fieldName: String) Creates an aggregation that collects all distinct values of a field across multiple stage inputs into an array.
AggregateFunction	average(expression: Expression) Creates an aggregation that calculates the average (mean) of values from an expression across multiple stage inputs.
AggregateFunction	average(fieldName: String) Creates an aggregation that calculates the average (mean) of a field's values across multiple stage inputs.
AggregateFunction	count(expression: Expression) Creates an aggregation that counts the number of stage inputs with valid evaluations of the provided expression.
AggregateFunction	count(fieldName: String) Creates an aggregation that counts the number of stage inputs where the input field exists.
AggregateFunction	countAll() Creates an aggregation that counts the total number of stage inputs.
AggregateFunction	countDistinct(expression: Expression) Creates an aggregation that counts the number of distinct values of an expression across multiple stage inputs.
AggregateFunction	countDistinct(fieldName: String) Creates an aggregation that counts the number of distinct values of a field across multiple stage inputs.
AggregateFunction	countIf(condition: BooleanExpression) Creates an aggregation that counts the number of stage inputs where the provided boolean expression evaluates to true.
AggregateFunction	first(expression: Expression) Creates an aggregation that finds the first value of an expression across multiple stage inputs.
AggregateFunction	first(fieldName: String) Creates an aggregation that finds the first value of a field across multiple stage inputs.
AggregateFunction	last(expression: Expression) Creates an aggregation that finds the last value of an expression across multiple stage inputs.
AggregateFunction	last(fieldName: String) Creates an aggregation that finds the last value of a field across multiple stage inputs.
AggregateFunction	maximum(expression: Expression) Creates an aggregation that finds the maximum value of an expression across multiple stage inputs.
AggregateFunction	maximum(fieldName: String) Creates an aggregation that finds the maximum value of a field across multiple stage inputs.
AggregateFunction	minimum(expression: Expression) Creates an aggregation that finds the minimum value of an expression across multiple stage inputs.
AggregateFunction	minimum(fieldName: String) Creates an aggregation that finds the minimum value of a field across multiple stage inputs.
AggregateFunction	rawAggregate(name: String, vararg expr: Expression) Creates a raw aggregation function.
AggregateFunction	sum(expression: Expression) Creates an aggregation that calculates the sum of values from an expression across multiple stage inputs.
AggregateFunction	sum(fieldName: String) Creates an aggregation that calculates the sum of a field's values across multiple stage inputs.

Public functions
AliasedAggregate	alias(alias: String) Assigns an alias to this aggregate.

Public companion functions

arrayAgg

fun arrayAgg(expression: Expression): AggregateFunction

Creates an aggregation that collects all values of an expression across multiple stage inputs into an array.

If the expression resolves to an absent value, it is converted to null. The order of elements in the output array is not stable and shouldn't be relied upon.

Parameters
expression: Expression	The expression to collect values from.

Returns
AggregateFunction	A new AggregateFunction representing the array_agg aggregation.

arrayAgg

fun arrayAgg(fieldName: String): AggregateFunction

Creates an aggregation that collects all values of a field across multiple stage inputs into an array.

If the expression resolves to an absent value, it is converted to null. The order of elements in the output array is not stable and shouldn't be relied upon.

Parameters
fieldName: String	The name of the field to collect values from.

Returns
AggregateFunction	A new AggregateFunction representing the array_agg aggregation.

arrayAggDistinct

fun arrayAggDistinct(expression: Expression): AggregateFunction

Creates an aggregation that collects all distinct values of an expression across multiple stage inputs into an array.

If the expression resolves to an absent value, it is converted to null. The order of elements in the output array is not stable and shouldn't be relied upon.

Parameters
expression: Expression	The expression to collect values from.

Returns
AggregateFunction	A new AggregateFunction representing the array_agg_distinct aggregation.

arrayAggDistinct

fun arrayAggDistinct(fieldName: String): AggregateFunction

Creates an aggregation that collects all distinct values of a field across multiple stage inputs into an array.

If the expression resolves to an absent value, it is converted to null. The order of elements in the output array is not stable and shouldn't be relied upon.

Parameters
fieldName: String	The name of the field to collect values from.

Returns
AggregateFunction	A new AggregateFunction representing the array_agg_distinct aggregation.

average

fun average(expression: Expression): AggregateFunction

Creates an aggregation that calculates the average (mean) of values from an expression across multiple stage inputs.

Parameters
expression: Expression	The expression representing the values to average.

Returns
AggregateFunction	A new AggregateFunction representing the average aggregation.

average

fun average(fieldName: String): AggregateFunction

Creates an aggregation that calculates the average (mean) of a field's values across multiple stage inputs.

Parameters
fieldName: String	The name of the field containing numeric values to average.

Returns
AggregateFunction	A new AggregateFunction representing the average aggregation.

count

fun count(expression: Expression): AggregateFunction

Creates an aggregation that counts the number of stage inputs with valid evaluations of the provided expression.

Parameters
expression: Expression	The expression to count.

Returns
AggregateFunction	A new AggregateFunction representing the 'count' aggregation.

count

fun count(fieldName: String): AggregateFunction

Creates an aggregation that counts the number of stage inputs where the input field exists.

Parameters
fieldName: String	The name of the field to count.

Returns
AggregateFunction	A new AggregateFunction representing the 'count' aggregation.

countAll

fun countAll(): AggregateFunction

Creates an aggregation that counts the total number of stage inputs.

Returns
AggregateFunction	A new AggregateFunction representing the countAll aggregation.

countDistinct

fun countDistinct(expression: Expression): AggregateFunction

Creates an aggregation that counts the number of distinct values of an expression across multiple stage inputs.

Parameters
expression: Expression	The expression to count the distinct values of.

Returns
AggregateFunction	A new AggregateFunction representing the count distinct aggregation.

countDistinct

fun countDistinct(fieldName: String): AggregateFunction

Creates an aggregation that counts the number of distinct values of a field across multiple stage inputs.

Parameters
fieldName: String	The name of the field to count the distinct values of.

Returns
AggregateFunction	A new AggregateFunction representing the count distinct aggregation.

countIf

fun countIf(condition: BooleanExpression): AggregateFunction

Creates an aggregation that counts the number of stage inputs where the provided boolean expression evaluates to true.

Parameters
condition: BooleanExpression	The boolean expression to evaluate on each input.

Returns
AggregateFunction	A new AggregateFunction representing the count aggregation.

first

fun first(expression: Expression): AggregateFunction

Creates an aggregation that finds the first value of an expression across multiple stage inputs.

Parameters
expression: Expression	The expression to find the first value of.

Returns
AggregateFunction	A new AggregateFunction representing the first aggregation.

first

fun first(fieldName: String): AggregateFunction

Creates an aggregation that finds the first value of a field across multiple stage inputs.

Parameters
fieldName: String	The name of the field to find the first value of.

Returns
AggregateFunction	A new AggregateFunction representing the first aggregation.

last

fun last(expression: Expression): AggregateFunction

Creates an aggregation that finds the last value of an expression across multiple stage inputs.

Parameters
expression: Expression	The expression to find the last value of.

Returns
AggregateFunction	A new AggregateFunction representing the last aggregation.

last

fun last(fieldName: String): AggregateFunction

Creates an aggregation that finds the last value of a field across multiple stage inputs.

Parameters
fieldName: String	The name of the field to find the last value of.

Returns
AggregateFunction	A new AggregateFunction representing the last aggregation.

maximum

fun maximum(expression: Expression): AggregateFunction

Creates an aggregation that finds the maximum value of an expression across multiple stage inputs.

Parameters
expression: Expression	The expression to find the maximum value of.

Returns
AggregateFunction	A new AggregateFunction representing the maximum aggregation.

maximum

fun maximum(fieldName: String): AggregateFunction

Creates an aggregation that finds the maximum value of a field across multiple stage inputs.

Parameters
fieldName: String	The name of the field to find the maximum value of.

Returns
AggregateFunction	A new AggregateFunction representing the maximum aggregation.

minimum

fun minimum(expression: Expression): AggregateFunction

Creates an aggregation that finds the minimum value of an expression across multiple stage inputs.

Parameters
expression: Expression	The expression to find the minimum value of.

Returns
AggregateFunction	A new AggregateFunction representing the minimum aggregation.

minimum

fun minimum(fieldName: String): AggregateFunction

Creates an aggregation that finds the minimum value of a field across multiple stage inputs.

Parameters
fieldName: String	The name of the field to find the minimum value of.

Returns
AggregateFunction	A new AggregateFunction representing the minimum aggregation.

rawAggregate

fun rawAggregate(name: String, vararg expr: Expression): AggregateFunction

Creates a raw aggregation function.

This method provides a way to call aggregation functions that are supported by the Firestore backend but that are not available as specific factory methods in this class.

Parameters
name: String	The name of the aggregation function.
vararg expr: Expression	The expressions to pass as arguments to the function.

Returns
AggregateFunction	A new AggregateFunction for the specified function.

sum

fun sum(expression: Expression): AggregateFunction

Creates an aggregation that calculates the sum of values from an expression across multiple stage inputs.

Parameters
expression: Expression	The expression to sum up.

Returns
AggregateFunction	A new AggregateFunction representing the sum aggregation.

sum

fun sum(fieldName: String): AggregateFunction

Creates an aggregation that calculates the sum of a field's values across multiple stage inputs.

Parameters
fieldName: String	The name of the field containing numeric values to sum up.

Returns
AggregateFunction	A new AggregateFunction representing the sum aggregation.

Public functions

alias

fun alias(alias: String): AliasedAggregate

Assigns an alias to this aggregate.

Parameters
alias: String	The alias to assign to this aggregate.

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