You can't really find them all in diamond, but you can either trade, or migrate from others games. Hope that answers your question
get an aciton replay and find the cheat for all Pokemon on Google then put it on ur action replay and get all the Pokemon.
you have to catch all of the pokemon in diamond or SEE all of the pokemon
get an action replay then get the "poke mod" otherwise known as Pokemon modifier and then find all the Pokemon.
You can find Pidey in a Pokemon Outbreak in Pokemon Diamond
You can find number 45 almost an where in Pokemon diamond and all you have to do in smear some honey on a tree and get number 45 which is the Pokemon Burmy that evolves into Wormadam
You can't. But you could migrate from diffrent regions
You find a soothe bell at the Pokemon mansion
You travel all over Sinnoh and then trade and/or migrate from other Pokemon
If you have a action replay, you can use it. Or if you have Pokemon pearl,you can find Palkia,if you have diamond find Dialga
I do not think there is one...if there is you would find it by typing in "all Pokemon diamond action replay codes"
Beat the Pokemon League, and you will be able to find all but one of the fossils of the ancient Pokemon. (For Diamond, all but Shieldon's fossil are available)
all the Pokemon on route 210 in Pokemon diamond and pearl are ponyta, geodude and if your really lucky you can find onix.
either from Cyrus or by matching all numbers in the Pokemon lotto