>creating GUI app in C
You asked that in the previous thread...and possibly ignored the answers.

>I studied my C++ books that I'd borrowed from my friend not completely and I know how to code in console and basic things and I know OOP in C++ some how but the problem is after I reviewed OOP what should I do ?

Write some programs within your capacity first... Programming isn't something you learn in a few days ...
And even after years... OS developing isn't something very easy to get into...(and you'd know that if you bothered to follow the links you were directed to)

>How connect C++ to the e.g oracle database ?
Like this