Sub-query to retrieve data from SQL database

[magicfun]

Since I need to use sub-query t retrieve data from database into dataset.

So shoud I (1) pass the sub-query into SqlDataAdapter directly, then fill into the dataset? Or (2)join the data table in the dataset to made the sub-query?

And for method (2), if I use data relationship, how can I write the sub-query?

Many thanks!!!