iterative query

any body know how i can transform a recursive query to iterative one?
if possible i need a simple example witth little explanation

Thanks alot.Please provide a sample of what you have now so that it would be easier to help you.|||

ok thanks before any thing,

it is for learnning purposes, i really have no example, but i have heard about it, so if possible if you can provide a simple scenario. with the conversion

thanks alot.