io.lettuce.core.search.arguments

Class AggregateArgs.GroupBy

java.lang.Object

io.lettuce.core.search.arguments.AggregateArgs.GroupBy

All Implemented Interfaces:

AggregateArgs.PipelineOperation

Enclosing class:

AggregateArgs

public static class AggregateArgs.GroupBy
extends Object
implements AggregateArgs.PipelineOperation

Represents a GROUPBY clause in an aggregation pipeline.

Groups the results in the pipeline based on one or more properties. Each group should have at least one reducer function that handles the group entries, either counting them or performing multiple aggregate operations.

Example Usage:

 {
     @code
     // Group by category and count items
     GroupBy groupBy = GroupBy.of("category").reduce(Reducer.count().as("item_count"));

     // Group by multiple fields with multiple reducers
     GroupBy complexGroup = GroupBy.of("category", "brand").reduce(Reducer.count().as("count"))
             .reduce(Reducer.avg("@price").as("avg_price")).reduce(Reducer.sum("@quantity").as("total_quantity"));
 }
 

Supported Reducers:

• COUNT - Count the number of records in each group
• SUM - Sum numeric values within each group
• AVG - Calculate average of numeric values
• MIN/MAX - Find minimum/maximum values
• COUNT_DISTINCT - Count distinct values
• COLLECT - Collect per-row field projections into an array of entries per group (experimental, see AggregateArgs.Reducer.collect())

Performance Note: Properties used in GROUPBY should be stored as SORTABLE in the index for optimal performance.

Constructor Summary

Constructors

Constructor and Description
GroupBy(List<String> properties)

Method Summary

Modifier and Type	Method and Description
void	build(CommandArgs<?,?> args) Build the operation arguments into the command args.
static AggregateArgs.GroupBy	of(String... properties) Static factory method to create a GroupBy instance.
AggregateArgs.GroupBy	reduce(AggregateArgs.Reducer reducer)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GroupBy

public GroupBy(List<String> properties)

Method Detail

reduce

public AggregateArgs.GroupBy reduce(AggregateArgs.Reducer reducer)

of

@SafeVarargs
public static AggregateArgs.GroupBy of(String... properties)

Static factory method to create a GroupBy instance.

Parameters:

properties - the properties to group by

Returns:

new GroupBy instance

build

public void build(CommandArgs<?,?> args)

Description copied from interface: AggregateArgs.PipelineOperation

Build the operation arguments into the command args.

Specified by:

build in interface AggregateArgs.PipelineOperation

Parameters:

args - the command args to build into