可以在IQueryable上使用linq将两列加在一起并按该列分组吗？

Question

My data comes from IQueryable that looks like the following table when I return all of the DailyCollectionActivities.

CatType | CdDescr | CollTypeDescr | RollCasteDescr | TIFDescr | TADescr | Amount
--------------------------------------------------------------------------------
Cat 1   | Cd 1    | CollType 233  | Roll Caste 234 | TIF 2344 | TA 2343 | 344.35
Cat 1   | Cd 1    | CollType 222  | Roll Caste 235 | TIF 2345 | TA 2344 | 355.35
Cat 2   | Cd 2    | CollType 223  | Roll Caste 236 | TIF 2346 | TA 2345 | 664.44
Cat 3   | Cd 3    | CollType 255  | Roll Caste 236 | TIF 2347 | TA 2346 | 455.34
Cat 4   | Cd 4    | CollType 266  | Roll Caste 236 | TIF 2348 | TA 2347 | 455.44

I'm trying to find out if it's possible, using linq on the IQueryable<DailyCollectionActivity> data, to add two columns together and then group on that newly created column? For example I need to figure out how to add CatType to CdDescr (CatType + '-' + CdDescr) and then group by that newly created column and sum the Amounts. Finally, I then need to take the results of that query and bind it to a RadGrid .

To make things more interesting, the user is allowed to choose which columns get added together. I could wind up with a group by clause like (CatType + '-' CdDescr), (TIFDescr + '-' + TADescr) .

Is this something that I can reasonably accomplish using Linq?

Answer 1

say its from categories

var result = from s in (

from p in categories
             select new {
TypeDesr = p.CatType+"-"+ p.CdDesr,
CollTypeDescr  = p.CollTypeDescr ,
RollCasteDescr = p.RollCasteDescr,
TIFDescr = p.TIFDescr,
TADescr = p.TADescr,
Amount = p.Amount
})
group s by s.TypeDesr into r
select r;