According to the Screens every thing is fine, but make sure that SFTP server is running in the target device so that application can be deployed into the target device.
I'm just realizing that what I was trying to do was maybe nonsense : I was trying to pass on to the mysql server a value for the client on which my Qt program is running i.e. I was trying to "deceive" the server. And I could understand then that there would be no such method in QSqlDatabase (and that you couldn't understand my question initially).
i think the only things you need to do is open or shutdown bluetooth, find bluetooth devices and connect if needed. all the other things must have been done by the hardware vendor
Got it. The documentation quite frankly is bad written when it comes to the QtCreatorDeployment.txt What you actually write in this file is just the remote path and without the sftp://IP_ADDRESS so now I simply have:
/home/pi/Projects/
and the binary from my Debian 8 lands right in there on the RPi2. I posted a detailed explanation on stackoverflow (link in my first post).