net.esper.eql.expression
Class AggregationServiceFactory
java.lang.Object
net.esper.eql.expression.AggregationServiceFactory
public class AggregationServiceFactory
- extends Object
Factory for aggregation service instances.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
AggregationServiceFactory
public AggregationServiceFactory()
getService
public static AggregationService getService(List<ExprAggregateNode> aggregateExprNodes,
boolean hasGroupByClause,
ExprNode optionalHavingNode,
List<ExprNode> sortByNodes)
- Returns an instance to handle the aggregation required by the aggregation expression nodes, depending on
whether there are any group-by nodes.
- Parameters:
aggregateExprNodes
- - aggregation nodes extracted out of the select expressionhasGroupByClause
- - indicator on whethere there is group-by required, or group-alloptionalHavingNode
- - having node if having-clause was specified, or null if no having-clause givensortByNodes
- - the nodes for the sort-by clause
- Returns:
- instance for aggregation handling