QSqlDatabase: QOpenOCCI driver not loaded QSqlDatabase: available drivers: <drivers> Error: opening DB failed because Driver not loaded
First make sure that the QOpenOCCI .so or .dll file is either installed in the qt sql plugin directory or that you have a sub directory in your project named sqldrivers with it. [http://doc.trolltech.com/4.3/plugins-howto.html]
On linux make sure that symlinks for occi libs are setup correctly...
cd /path/to/instantclient_11_1/ ln -sf libclntsh.so.11.1 libclntsh.so