TFPExprNode.InitAggregate procedure

Declaration

procedure InitAggregate; virtual

Description

The InitAggregate virtual method initializes aggregate processing state for nodes that participate in aggregate operations. It is called at the beginning of an aggregate processing cycle to reset counters, accumulators, and other aggregate state.

For most expression nodes, this method does nothing (default implementation). However, nodes representing aggregate functions (like SUM, COUNT, AVG) override this method to initialize their aggregation state.