>>Thank you for reply me first. You mean i should use one dataset. But if i have 2 database (2 dataset).
>>How can i do. May you give some information to me.
>
>You can add all the tables from one dataset to the first dataset.

Something like this:
ds200.tables.add(ds300.tables(0))
ds200.tables.add(ds300.tables(1))
ds200.tables.add(ds300.tables(2))
ds200.tables.add(ds300.tables(..))
ds200.tables.add(ds300.tables(n))

Or even better, loop through all the tables dynamically