TAggregateSum class
Internally used class for sum aggregate functions
Declaration
TAggregateSum = class(TAggregateExpr)Inheritance
Descends from it: TAggregateAvg
Description
The TAggregateSum class implements the sum aggregate function,
which calculates the total of all processed numeric values.
It extends TAggregateExpr to provide summation-specific aggregation logic.
The class maintains an internal accumulator that adds each new value to the running total. It handles different numeric types (integers, floats, currency) and performs appropriate type conversions to maintain precision during the summation process.
The sum function ensures type safety by converting arguments to compatible numeric types before performing addition operations. The final result type depends on the types of values processed during aggregation.
This class is used internally by the TFPExpressionParser class to construct an AST (Abstract Syntax Tree). There is normally no need for you to use or instantiate this class directly.
See also
Methods
ConvertArgument | public | Convert argument for sum aggregation |
InitAggregate | public | Initialize sum aggregation |
UpdateAggregate | public | Update sum aggregate with new value |
Inherited
From TAggregateExpr (2)
From TFPExprFunction (8)
ArgumentNodes ArgumentParams AsString CalcParams Check 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.