I believe your problem is that you're using the wrong driver. According to the Qt documentation, you need to be using the ODBC driver for DSN files to work - for example:
db = QSqlDatabase::addDatabase("QODBC");
Also note that, again according to the Qt documentation, if you're trying to pass a DSN filename to setDatabaseName
, then it MUST have a ".dsn" file extension:
For the QODBC driver, the name can either be a DSN, a DSN filename (in which case the file must have a .dsn extension), or a connection string.
And, finally, it must be listed in your odbc.ini.