thank you the answer Mend
ok i understands and agree with A & B but i do have some questions about C:

are you saying i should build classes for my db tables and every time i need to get info from certain table i'll create an instance of that table class and use the data i need ?

also, what with Queries that involves INNER JOIN ?, I'm sure that i'm still don't see the big picture, but i think i'm getting there, i really want to understand this concept please explain a bit more