Read InTransaction at runtime to ascertain whether a transaction is currently active for the SQL connection component. If the connection component is currently in a transaction, all communication with the server that passes through the connection is enlisted in that transaction.  

InTransaction is true if there is an active transaction. If no transaction is active, InTransaction is false. 

A transaction begins when the application calls BeginTransaction and lasts until the application calls CommitFreeAndNil, RollbackFreeAndNil, or RollbackIncompleteFreeAndNi. If there are multiple transactions, InTransaction remains true until all transactions are either committed or rolled back. 

BeginTransaction 

CommitFreeAndNil 

RollbackFreeAndNil 

RollbackIncompleteFreeAndNi 

TransactionsSupported 

TransactionLevel 

MultipleTransactionsSupported