Question

I am trying to understand how to do a Sum when I need to only use the Max/top values for a date period. This is kind of like SQL Server: SELECT only the rows with MAX(DATE) but not exactly. Thanks for reading.

declare @tbl Table ( tableid int , eventdate date,  valuec char(5) , valued int , recordedwhen datetime2(3) )
insert into @tbl values ( 0 , '2012-03-22' , '11111' , 3 , '2012-03-23 17:21:01.083' )
insert into @tbl values ( 1 , '2012-03-22' , '22222' , 3 , '2012-03-23 17:21:01.083' )
insert into @tbl values ( 2 , '2012-03-22' , '22222' , 4 , '2012-03-23 18:21:01.083' )
insert into @tbl values ( 3 , '2012-03-22' , '22222' , 5 , '2012-03-23 18:21:01.083' )

select 
        eventdate, valuec , sum(valued) as valuedSum , recordedwhen
        from 
        @tbl
        group by eventdate, valuec, recordedwhen

I get three rows. But what I actually want is this:

--   
--   eventdate  valuec valuedSum   recordedwhen
--   ---------- ------ ----------- ----------------------
--   2012-03-22 11111  3           2012-03-23 17:21:01.08
--   2012-03-22 22222  9           2012-03-23 18:21:01.08

I do not want the row where tableid=1 because that is part of an older batch of data.
The newer rows represent a later insert (all recordedwhen values with the same datetime are the same for a batch)

So if a new row was inserted like this:

insert into @tbl values ( 4 , '2012-03-22' , '22222' , 6 , '2012-03-24 18:21:01.083' )

Then the data would should like this:

--   eventdate  valuec valuedSum   recordedwhen
--   ---------- ------ ----------- ----------------------
--   2012-03-22 11111  3           2012-03-23 17:21:01.08
--   2012-03-22 22222  6           2012-03-24 18:21:01.08

Answer 1

You basically need two selects. You can do either an inner select, or CTE. The following produces the result you desire

create table #tbl ( tableid int , eventdate date,  valuec char(5) , valued int , recordedwhen datetime2(3) )
insert into #tbl values ( 0 , '2012-03-22' , '11111' , 3 , '2012-03-23 17:21:01.083' )
insert into #tbl values ( 1 , '2012-03-22' , '22222' , 3 , '2012-03-23 17:21:01.083' )
insert into #tbl values ( 2 , '2012-03-22' , '22222' , 4 , '2012-03-23 18:21:01.083' )
insert into #tbl values ( 3 , '2012-03-22' , '22222' , 5 , '2012-03-23 18:21:01.083' )
insert into #tbl values ( 4 , '2012-03-22' , '22222' , 6 , '2012-03-24 18:21:01.083' )

;
with t (eventdate, valuec, maxrecordedwhen)
as (select eventdate, valuec, max(recordedwhen)
    from #tbl
    group by eventdate, valuec)
select t.eventdate, t.valuec, sum(valued) as valuedsum, maxrecordedwhen
from t
    join #tbl on t.eventdate = #tbl.eventdate and t.valuec = #tbl.valuec
where t.maxrecordedwhen = #tbl.recordedwhen
group by t.eventdate, t.valuec, t.maxrecordedwhen

drop table #tbl

Notice that the maximum batch date is found in the CTE and then used to filter the summation result.