function TfrmActMain.dbConnect(var DB: TpFIBDatabase;
  var transaction: TpFIBTransaction; var query: TpFIBQuery): Boolean;
begin
  try
    DB := TpFIBDatabase.Create(nil);
    query := TpFIBQuery.Create(nil);
    transaction := TpFIBTransaction.Create(nil);

    query.Database := DB;
    query.transaction := transaction;
    query.Options := [qoStartTransaction, qoAutoCommit];
    transaction.DefaultDatabase := DB;

    DB.dbname := dbserver + ':' + dbname;
    DB.ConnectParams.UserName := dbusername;
    DB.ConnectParams.Password := dbpassword;
    DB.Connected := true;
    Result := true;
  except
    on E: Exception do
    begin
      AddToLog('dbconnect :' + E.Message);
      Result := false;
    end;

  end;
end;

dbConnect(DB, tr, query);

try
   with query do
	begin
	  sql.Clear;
	  sql.Add('INSERT INTO Data' +'(поля таблицы )' + ' values ' + '(значения)');
	  ExecQuery;
	end;

except
	on E: Exception do
	  AddToLog('%d: Ошибка сохранения данных %s', [data^.DeviceID, E.Message]);
end;

try
	DB.Connected := false;
	query.Free;
	tr.Free;
	DB.Free;
except
	on E: Exception do
	  AddToLog('%d: Ошибка освобождения ресурсов %s',
		[data^.DeviceID, E.Message]);
end;

public string GetLayer_admin()
{
string layer = "Не найдено";
            fb.Open();
FbCommand SelectSQL = new FbCommand("select LAYER from LAYERS", fb);
FbTransaction fbt = fb.BeginTransaction();
SelectSQL.Transaction = fbt;
FbDataReader reader = SelectSQL.ExecuteReader();
 
try
{
    while (reader.Read()) { layer = reader.GetString(0); }
}
finally
{
    fbt.Commit();
    reader.Close();
    SelectSQL.Dispose();
}
 
return layer;
}