Declaration¶
Source position: fpexprpars.pp line 696
type
TAggregateCount = class(TAggregateExpr)
public
procedure InitAggregate;
procedure UpdateAggregate;
end;
Inheritance¶
Description¶
The TAggregateCount class implements the count aggregate function, which counts the number of values processed during aggregation. It extends TAggregateExpr to provide count-specific aggregation logic.
Unlike other aggregate functions that process the actual values, the count function simply increments a counter for each value encountered, regardless of the value's content or type. This makes it useful for determining the number of records or values in a dataset.
The count function always returns an integer result representing the total number of values processed during the aggregation cycle.
Methods¶
| Member | Visibility | Description |
|---|---|---|
| InitAggregate | public | Initialize count aggregation |
| UpdateAggregate | public | Update count aggregate with new value |
See also¶
| Name | Description |
|---|---|
| TFPExprNode | Class for representing nodes in expression trees |