Сразу бросаются в глаза фразы:| Цитата(Delphi Help) | | DataSet contains abstract methods, and is not intended to be used in applications. Instead, applications instantiate dataset descendants such as TClientDataSet, TADODataSet, TTable, TQuery, TStoredProc, or TSQLDataSet. |
| Цитата(там же) | TDataSet introduces the basic properties, events, and methods for working with data. Many of these properties, events, and methods are abstract (Delphi) or pure virtual (C++) in TDataSet. Abstract or pure virtual declarations are declarations without implementations. At the TDataSet level they cannot be used or accessed. Developers must use or derive descendants of TDataSet that redeclare and implement these abstract or pure virtual methods. Many of the other TDataSet methods are declared and implemented in TDataSet as virtual methods, but the implementations are merely stubs that are reimplemented in descendants.
TDataSet has several descendants: TBDEDataSet, TCustomADODataSet, TIBCustomDataSet, TCustomSQLDataSet, and TCustomClientDataSet. |
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