Use TADCustomTransaction to manage transactions in a connection to a DBMS. 

The component, at first, is target to Interbase / Firebird client application developers. Because these DBMS's are supporting multiple active transactions per a connection. If a DBMS does not support this feature, then multiple TADCustomTransaction objects on the same connection will share control under the same single transaction. Also, the application may use TADCustomConnection transaction control methods. 

This class hides some of properties, allowing to control visibility of properties by descendant classes. End users should use TADTransaction.

TADCustomTransaction = class(TADComponent, IADPhysTransactionStateHandler);

Managing Transactions, Establishing Connection, TADTransaction, TADCustomConnection