com.yahoo.bard.webservice.sql.aggregation

Class DruidSqlAggregationConverter

java.lang.Object

com.yahoo.bard.webservice.sql.aggregation.DruidSqlAggregationConverter

All Implemented Interfaces:

BiFunction<Aggregation,ApiToFieldMapper,Optional<SqlAggregation>>

public class DruidSqlAggregationConverter
extends Object
implements BiFunction<Aggregation,ApiToFieldMapper,Optional<SqlAggregation>>

The default implementation of mapping from Druid's Aggregation to a SqlAggregation.

Constructor Summary

Constructors

Constructor and Description
DruidSqlAggregationConverter() Constructors a map from druid to sql aggregations using getDefaultDruidToSqlAggregation().
DruidSqlAggregationConverter(Map<String,SqlAggregationType> druidToSqlAggregation) Use the given map for converting from druid to sql aggregations.

Method Summary

Modifier and Type	Method and Description
Optional<SqlAggregation>	apply(Aggregation aggregation, ApiToFieldMapper apiToFieldMapper) Finds the corresponding SqlAggregation from a druid aggregation.
static Map<String,SqlAggregationType>	getDefaultDruidToSqlAggregation() The default mapping from druid to sql aggregations defined by DefaultSqlAggregationType.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.BiFunction

andThen

Constructor Detail

DruidSqlAggregationConverter

public DruidSqlAggregationConverter()

Constructors a map from druid to sql aggregations using getDefaultDruidToSqlAggregation().

DruidSqlAggregationConverter

public DruidSqlAggregationConverter(Map<String,SqlAggregationType> druidToSqlAggregation)

Use the given map for converting from druid to sql aggregations.

Parameters:

druidToSqlAggregation - The mapping from Druid aggregation name to Sql aggregation type.

Method Detail

getDefaultDruidToSqlAggregation

public static Map<String,SqlAggregationType> getDefaultDruidToSqlAggregation()

The default mapping from druid to sql aggregations defined by DefaultSqlAggregationType.

Returns:

the mapping from druid aggregation names to sql aggregation types.

apply

public Optional<SqlAggregation> apply(Aggregation aggregation,
                                      ApiToFieldMapper apiToFieldMapper)

Finds the corresponding SqlAggregation from a druid aggregation.

Specified by:

apply in interface BiFunction<Aggregation,ApiToFieldMapper,Optional<SqlAggregation>>

Parameters:

aggregation - The druid aggregation, i.e. LongSumAggregation.

apiToFieldMapper - the mapping from api name to field name of the aggregation.

Returns:

the supported sql aggregation type.