What platform are you on? What error are you seeing? If you're simply not retrieving the data then most likely the DB file isn't where SQLite is looking for it. It's best to check first with QFileInfo to make sure the file exists(), isReadable(), and isWriteable(). Then you know you have the right location.

(Also, you need to double up your backslashes, or use forward slashes and QDir::toNativeSeparators() to create the file path for setDatabaseName().)