Is there any qt signal for sql database change?

Question

I wrote a C++ program using Qt. some variables inside my algorithm are changed outside of my program and in a web page. every time the user changes the variable values in th

Answer 1

There is no such thing. The Qt event loop and the database are not connected in any way. You only fetch/alter/delete/insert/... data and that's it. Option 1 is the one you have to do. There are ways to use TRIGGER on the server side to launch external scripts but this would not help you very much.