TAggregateCount class
Internally used class for count aggregate functions
Declaration
TAggregateCount = class(TAggregateExpr)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.
See also
Methods
InitAggregate | public | Initialize count aggregation |
UpdateAggregate | public | Update count aggregate with new value |
Inherited
From TAggregateExpr (2)
From TFPExprFunction (9)
ArgumentNodes ArgumentParams AsString CalcParams Check ConvertArgument CreateFunction Destroy HasAggregate
From TFPExprIdentifierNode (3)
From TFPExprNode (2)
From TObject (41)
AfterConstruction BeforeDestruction CheckDisposed ClassInfo ClassName ClassNameIs ClassParent ClassType CleanupInstance Create DefaultHandler DefaultHandlerStr Dispatch DispatchStr Disposed DisposeOf Equals FieldAddress Free FreeInstance GetDisposed GetHashCode GetInterface GetInterfaceByStr GetInterfaceEntry GetInterfaceEntryByStr GetInterfaceTable GetInterfaceWeak GetLastCastErrorInfo InheritsFrom InitInstance InstanceSize MethodAddress MethodName newinstance QualifiedClassName SafeCallException StringMessageTable SystemHasExtendedRTTI ToString UnitName
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.