Qt Code: 
  1. Generator::Generator(const QString &databasePath)
  2. {
  3.   QString name = databasePath;
  4.   name = name.replace("\\","/");
  5.   database = QSqlDatabase::addDatabase("QSQLITE");
  6.   database.setDatabaseName(name);
  7.   if(database.open())
  8.   {
  9.     Logger::info("Database " + databasePath + " opened successfuly.");
  10.   }
  11.   else
  12.   {
  13.     Logger::error("Couldn't open database " + databasePath + "! Error: " + database.lastError().text() + ". Application aborted.");
  14.     exit(-2);
  15.   }
  16. }
  17.  
  18. Generator::~Generator()
  19. {
  20.   if (database.isOpen())
  21.   {
  22.     database.close();
  23.   }
  24. }
  25.  
  26. void Generator::generateDictionaryFile()
  27. {
  28.   QSqlQuery query(database);
  29.   query.exec("select distinct ulica from AdresyKody_mid_mif");
  30.   Logger::info("Last error: " + query.lastError().text());
  31.   while(query.next())
  32.   {
  33.     Logger::info("Got from database: " + query.value(0).toString());//national characters here
  34.   }
  35. }
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But the issue is solved already.In other place I had code in Logger
Qt Code: 
  1. logFile.write(logText.toLatin1());
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and as it turned out that was the source of my issues.After change to:
Qt Code: 
  1. logFile.write(logText.toUtf8());
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all works fine.

Sorry mates for bothering you for nothing.