How do I get the sum of each numeric fields from multiple DataTables with similar keys and return one row (not looking for Merge)?

Hi,

I have 3 DataTables (dtFdnCum, dtFdnNov, dtDMPFdn0211) with same schema.  I have 3 fields as part of the key and each DataTable can have the same key.  I want to combine the contents of the 3 DataTables, in the event there are same keys, all the numeric fields should be summed up and generate a single row.  Am not looking for a Merge as it doesn't perform a summation of similar keys.

Am trying to get a result similar to what the SQL below will generate:
SELECT cat_desc, camp_code, src_code,sum(day_cnt),sum(day_amt),sum(day_avg),sum(mon_cnt),sum(mon_amt),sum(mon_avg),sum(year_cnt),sum(year_amt),sum(year_avg),sum(cumul_cnt),sum(cumul_amt),sum(cumul_avg) FROM dtFdnCum, dtFdnNov, dtDMPFdn0211 group by cat_desc, camp_code, src_code;

Language is C#.  Thanks.Start Free Trial