Question

I am stuck in a sql query. I have data like:

IdentityId  ProductId   TypeId   Rating
3           1             1      9
7           1             2      3
9           500           1      7
2           500           2      5
8           777           4      5
12          777           3      8
11          999           4      1

I need to the maximum Rating of each Product + i need the typeId associated with that Rating.

So the Product 1 have the maximum Rating 9 & the TypeId associated is 1

Product 500 have the maximum Rating 7 & the TypeId associated is 1

Product 777 have the maximum Rating 8 & the TypeId associated is 3

Product 999 have the maximum Rating 1 & the TypeId associated is 4

like below output:

ProductId   TypeId   Rating
1           1        9
500         1        7
777         3        8
999         4        1

Please ask me if the question is not clear.

Thanks for your valuable time & help.

Answer 1

declare @T table
(
  IdentityId int,
  ProductId int,
  TypeId int,
  Rating int
)

insert into @T values  
(3,           1,             1,      9),
(7,           1,             2,      3),
(9,           500,           1,      7),
(2,           500,           2,      5),
(2,           777,           4,      5),
(12,          777,           3,      8),
(2,           999,           4,      1)

;with C as
(
  select ProductId,
         TypeId,
         Rating,
         row_number() over(partition by ProductID 
                           order by Rating desc) as rn
  from @T
)
select ProductId,
       TypeId,
       Rating
from C
where rn = 1
order by ProductId