Where can you trade from Pokemon diamond to emerald and how to do have..

You have to have the National Dex to be able to trade. When you get the National Dex, at the main screen(Place where you start new game or continue)it will say "Migrate to emerald". This is when you can trade from emerald.


(P.S.-This can also be done in Ruby, Sapphire, FireRed and LeafGreen)

You can't trade to GBA games, it's called Transferring. After you beat the Elite Four and complete the Sinnoh Pok�Dex, you can go to Pal Park and transfer the Pok�mon from GBA games from there.

When you bat the elite 4 and get the national pokedex you can visit pal park thats where you can get the Pokemon from emerald or ruby, saphire, firered, and leafgreen. But you can only get from the gba game after that you CANT trade back.

It's techincally not a trade, but a transfer from Emerald to Diamond (/Pearl).
Once you have the national dex, go south from Sandgem Town. You were just there, anyway, to get it. Anyway, go along route 219, 220, and 221. At the end, you'll find a building. If you were there before you got the national dex, it was blocked off. Now, it's unlocked. That building is the "Pal Park". Go in it, talk to Oak, etc. Save here and turn off the DS. Now, insert your Emerald in the game pocket on the DS, and turn it on. Go to Diamond, and press start at the start screen. There, you would normally click "Continue", but go down to "Import Emerald". Click that, and choose 6 Pokemon in your PC to import from emerald to diamond. Once that's all done, the game would restart. Now, you continue. Talk to the guy behind the counter, and he'll give you 6 special balls, which are more or less master balls. Now you go out into Pal Park and catch the 6 Pokemon that were imported.

There are numerous fields to catch the Pokemon in, and you'll want to find the Pokemon that correspond to that field. For example, a water Pokemon you transferred would be found in a lake or ocean. Moreover, a Psyduck, for example, would be found in the lake whereas a Staryu would be found in the ocean. There are also moutain ranges, valleys, and plain fields to catch Pokemon in. A regirock would be found on the mountain. A magnetite would be found in the valleys. Any other Pokemon that doesn't fit in the other areas would be found in the grass. It's all simple. I'm pretty sure you get the idea?