Special SQL query on SQL Server 2005 with sum()

I have a table T1, says with column C1,C2 and C3
I need the sum of C2
But first there is a condition on C3 : easy : select ... where C3 = 'MyData'
But in fact I only need the sum of maximum values C2 regarding value of C1
I explain with a sample table T1

C1   C2       C3
A       5       MyData
A     10       MyData
A     15       MyData
B    100       MyData
B     10       MyData

The sum here show be the one for C1 = 'A' third line 15 which is the max with C1 = 'A' + the one for C2 = 'B' where the max value is 100

So here, my select should return 115

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Steve WalesSenior Database AdministratorCommented:
I believe that this will get you what you need.

select sum(c2) from
select c1, max(c2) as c2
from t1
where c3 = 'MyData'
) as a

Open in new window

create table #table
      C1 char(1),
         C2 integer,
      C3 varchar(200)

insert into #table values ('A', 5, 'MyData')
insert into #table values ('A', 15, 'MyData')
insert into #table values ('B', 100, 'MyData')
insert into #table values ('B', 10, 'MyData')

      sum(maxc2) as total
            max(c2) as maxc2
      group by
) subset

Bhavesh ShahLead AnalysistCommented:

just little modify to sjwales query

select sum(c2) from
select t1.c1, max(c2) as c2
from t1
where c3 = 'MyData'
GROUP BY t1.c1
) as a

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awking00Information Technology SpecialistCommented:
>>The sum here show be the one for C1 = 'A' third line 15 which is the max with C1 = 'A' + the one for C2 = 'B' where the max value is 100<<
Did you mean the one where C1='B' and the max value is 100? If so, you can also use analytics.
select sum(x.c2) as sumc2 from
(select c2, row_number() over (partition by c1 order by c2 desc) rn
 from t1
 where c3 = 'MyData') as x
where x.rn = 1;
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Microsoft SQL Server

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