Many thanks for clearing my doubt with related examples. These type of things can only be learned either by hands on experience or by asking experienced forum users. Sadly I'am novice in TSQL so fall into second category.
Thanks again.
Regards,
Ombir
Thanks for your feedback. Just keep it mind that every experienced once was a novice. Keep learning and some hardworking you will become a expert one day and best of luck for your future.;-)