c++ - QtSql connection -

I am trying to create a connection in the database and let the database insert / delete / query I know SQL well but can not wrap my head around it in QT. I used to program in Delphi.

This is my code so far:

  QSqlDatabase db; Db.addDatabase ("QSQLITE"); Db.setHostName ("localhost"); // I do not know if I should include it, then the database is in the same directory as my program db.setDatabaseName ("Xmato.odb"); Db.setUserName (""); // no username is db.setPassword (""); // no password is db.open (); Db.prepare ("select from member"); Db.exec ();   
 I've added it to my .pro file:  
  QT + = sql;   
 QtSql included in my main file.  
 When I run this code, I get an error:  
  QSqlQuery :: ready: do not open the database   
 Any thoughts would greatly appreciate me.  
 PS: I use C ++ on Linux Ubuntu 12.04 and use LibreOffice Base to create my database.   
 
 
 After some little google-ing - Internal Database of OpenOffice Libraries  HSQLDB  (Option for natural java). .  
 It appears that some versions of the OpenLife Base are also able to connect, I recommend installing some settings that are more accessible to C ++, especially Qt.  
  
 This means that depending on the usage of the database, anyone may need to obtain additional source code (or packages) and a plugin / DLL / compilation library The QtSql module is dynamically loaded (i.e. run-time). I have participated in it for this.  
 When you receive all that setup, then the call should match the type of database to add you.  
  QSqlDatabase:: AddDatabase ("QODBC"); // MSSQL QSqlDatabase :: addDatabase ("QSQLITE") for something like; // SQLite QSqlDatabase :: addDatabase ("QMYSQL"); // MySQL for   
 Individually, if you are doing this only for kick, then a quick and easy database is SQLite