its there for when you get an oaks letter but if you have an action replay you can get it using an action replay code however if you don't you would have to get it from a shaymin event
No, there is not a Pokedex after the National Pokedex in Pokemon Diamond Version.
press switch pokedex on the national pokedex and you will be using the sinnoh pokedex
The National Pokedex is given to you once the Elite Four is defeated.
There is no other pokedex.
In Pokemon Diamond and Pearl you need the National Pokedex to get Magnemite. In Pokemon Platinum you don't need the National Pokedex to get Magnemite.
Well, since there is no number 117 in the local pokedex in Pokemon Diamond, we have to look into the national pokedex. In the national pokedex, number 117 is Seadra. Number 117 in the Sinnoh Pokedex is Wooper, can be found in the great marsh or on route 212
well you need to have all your Pokemon in your pokedex and when you get your national pokedex you will get breed
There is no way you have to compleate the pokedex but most of it is at the gyms.
146 is Uxie on sinnoh pokedex On National pokedex it is Moltres
You can get the National Pokedex in Diamond when you see all 150 Pokemon, but not necessarily capture them.
in the national pokedex: arceas in the regular pokedex: dialga
104 before the national pokedex expansion