object FDConnection: TFDConnection
  ...
  object FDTransactionSeveralOpers: TFDTransaction
    Options.Isolation = xiReadCommitted
    Options.AutoStart = False
    Options.AutoStop = False
    Options.DisconnectAction = xdRollback
    Connection = FDConnection
  ...
  object FDQuerySeveralOpers: TFDQuery
    BeforeOpen = FDQuerySeveralOpersBeforeOpen
    BeforeExecute = FDQuerySeveralOpersBeforeExecute
    Connection = FDConnection
    Transaction = FDTransactionSeveralOpers
  ...
  end

[FireDAC][Phys][FB]deadlock
update conflicts with concurrent update
concurrent transaction number is 9204

FDQuerySeveralOpers.Transaction.StartTransaction;

...

try
  FDQuerySeveralOpers.ExecSQL;
except on e: Exception do
begin
  //разбор exception, вывод сообщения об ошибке
  
  ...

  if (FDQuerySeveralOpers.Transaction.Active) then
    DataMod.FDQuerySeveralOpers.Transaction.Rollback;

  exit;
end;
end;

DataMod.FDQuerySeveralOpers.Close; //в случае успеха
DataMod.FDQuerySeveralOpers.Transaction.Commit; //в случае успеха

  with (DataMod.FDQuery) do
  begin
    if (Active) then
      Close;

    if (Transaction.Active) then
      Transaction.Rollback;
  end;


  with (DataMod.FDQueryMultiple) do
  begin
    if (Active) then
      Close;

    if (Transaction.Active) then
      Transaction.Rollback;
  end;