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RollbackTran

function RollbackTran: Boolean;

Example​

procedure CancelDatabaseWork(const Data: TvxDBDef);
begin
  if not Data.RollbackTran then
    raise Exception.Create('One or more database rollbacks failed');
end;

Usage​

RollbackTran sequentially rolls back active transactions on a data definition's database connections until all finish or the first rollback call raises.

  • Always inspect the Boolean result and assume cleanup may be incomplete when false.
  • A true result means no function call raised; it does not prove that a transaction existed or that every prior external effect was reversible.
  • Rollback cannot undo a connection already committed by an earlier step or by a partial CommitTran.

Additional Technical Info​

RollbackTran asks the configured database connections to roll back their current transactions in list order.

Source-backed behaviour​

If the data definition's internal transaction-started flag is true, the method logs one rollback message and clears that flag. It still enters the connection loop when the flag was already false.

For each DBCons[index], Velox calls the linked TvxDBCon.vxRollbackTran. Transactions disabled in that connection and connections with no active transaction are silent successful no-ops. An actual active DBX transaction is rolled back and freed. The group method does not inspect the lower-level Boolean, so normal completion returns true even if every connection was a no-op or the list was empty.

If a connection call raises, the exception is logged, the result becomes false and the while Result condition prevents later connections from being visited. This contradicts the nearby source comment that says rollback will carry on. Earlier connections may have rolled back while later ones remain active.

Created 2026-07-15