Question

Say I have a summary table like this:

AcitivityCache
(
   pkId (bigint, PK),
   Date (DateTime),
   OfficeId (int, FK)
   TransactionCount (int),
   RejectCount (int),
   InvitationCount (int),
   RequestCount (int)
   ...
   --more counts here--
   ...
)

Now I need to fetch the total of the counts over a time period (no grouping by office, just sums) which I can do with SQL like this:

 SELECT SUM(TransactionCount) as TotalTxCount, SUM(RejectCount) as TotalRejectCount, ...
 FROM ActivityCache 
 WHERE [Date] between '2011-02-01' and '2012-02-01'

How can I achieve that with linq?
Most solutions I have seen so far have some grouping. But for this case, I need no grouping, just the totals. I can do like this:

DateTime dateFrom, toDate; // initialized later
...
var q = dbContext.ActivityCaches
                 .Where(a=> a.Date > fromDate && a.Date <= toDate)
                 .GroupBy(a=> 1)
                 .Select(g=> new 
                             {
                                TotalTransactionCount = g.Sum(a => a.TransactionCount),
                                TotalRejectCount = g.Sum(a => a.RejectCount),
                                ...
                                ...
                             });

Or, I can fetch the columns first, then take sum programmatically.
Or, I can use an SP (dont like in this case).
Any better ideas (without group by)?

P.S: I wont be able to change the db schema

Answer 1

I don’t think LINQ to Entities has some nice query for this situation.

Another solution is using using Entity SQL (ESQL)

var fromDate = new DateTime(2011, 02, 01);
var toDate = new DateTime(2012, 02, 01);
var esql = @"select 
          sum(it.TransactionCount) as SumOfTransactionCount,
          sum(it.RejectCount) as SumOfRejectCount
               from ActivityCaches as it
               where it.Date > @fromDate and it.Date <= @toDate";
var query = CreateQuery<DbDataRecord>(esql,
        new ObjectParameter("fromDate", fromDate) ,
        new ObjectParameter("toDate", toDate));