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Base expression node that represents an aggregation function such as 'sum' or 'count'. In terms of validation each concrete aggregation node must implement it's own validation. In terms of evaluation this base class will ask the assigned net.esper.eql.core.AggregationResultFuture for the current state, using a column number assigned to the node. Concrete subclasses must supply an aggregation state prototype node net.esper.eql.core.Aggregator that reflects each group's (there may be group-by critera) current aggregation state.

Namespace: net.esper.eql.expression
Assembly:   NEsper (in NEsper.dll)

Syntax

Visual Basic (Declaration)
Public MustInherit Class ExprAggregateNode _
	Inherits ExprNode
C#
public abstract class ExprAggregateNode : ExprNode
Visual C++
public ref class ExprAggregateNode abstract : public ExprNode

Inheritance Hierarchy

See Also