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AggregateFunction

class AggregateFunction

A class that represents an aggregate function.

Summary

Public companion functions
`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`	`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

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.

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.