.net - LINQ Group By and aggregate fields -


i've struggled grouping in linq, i'd group based on date part of datetime field , aggregate other fields.

example table layout

mydatefield     myintfield1    myintfield2    myintfield3 01/02/2013      5              5              5 01/02/2013      5              5              5 02/02/2013      10             10             10 02/02/2013      10             10             10

i'd return list with

mydatefield     myintfield1    myintfield2    myintfield3 01/02/2013      10             10             10 02/02/2013      20             20             20

i've managed following using msdn examples can't head around how use it. states should able access new bookedlist group keep getting annonymous type errors , such.

        dim bestdays = in b                         a.bookedon < a.eventdaytime , a.cancelled = false                         group bookdate = a.bookedon.value.date                         bookedlist = group

the syntax into [field_name1] = [aggregate_function1]([value1]), [field_name2] = [aggregate_function2]([value2]) .... key automatically part of returned object.

so looking this:

class tablerow   public property mydatefield date   public property myintfield1 integer   public property myintfield2 integer   public property myintfield3 integer   sub new(mydate date,           myint1 integer, myint2 integer, myint3 integer)     mydatefield = mydate     myintfield1 = myint1     myintfield2 = myint2     myintfield3 = myint3   end sub end class  sub main()   dim tablesrows new list(of tablerow)   tablesrows.add(new tablerow(today, 5, 10, 15))   tablesrows.add(new tablerow(today, 6, 11, 16))    dim v = r in tablesrows group r.mydatefield           total1 = sum(r.myintfield1),                total2 = sum(r.myintfield2),                total3 = sum(r.myintfield3) end sub

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