c# - Select multiple fields group by and sum -

i want query linq (list of objects) , don't know how it, can group , sum can't select rest of fields. example:

id  value     name   category 1   5         name1  category1   1   7         name1  category1 2   1         name2  category2 3   6         name3  category3 3   2         name3  category3 

i want group id, sum value , return fields this.

id  value     name   category 1   12        name1  category1   2   1         name2  category2 3   8         name3  category3 

updated : if you're trying avoid grouping fields, can group id:

data.groupby(d => d.id)     .select(         g => new         {             key = g.key,             value = g.sum(s => s.value),             name = g.first().name,             category = g.first().category          }); 

but code assumes each id, same name , category apply. if so, should consider normalizing @aron suggests. imply keeping id , value in 1 class , moving name, category (and whichever other fields same same id) class, while having id reference. normalization process reduces data redundancy , dependency.