How to find the row associated with the min/max of a column?

Question

So basically I have some simple SQL code that looks like the following;

SELECT 
       [Column1]
      ,[Column2]
      ,[Column3]
      ,[Column4]
      ,MIN([Column5]) AS maxColumn5
      ,MAX([Column6]) AS minColumn6
      ,SUM([Column7]) AS sumColumn7
      ,SUM([Column8]) AS sumColumn8
      ,SUM([Column9]) AS sumColumn9

FROM 
    [tableName]

GROUP BY 
        [Column1]
       ,[Column2]
       ,[Column3]
       ,[Column4]

What I am trying to do is also find the column either 'Column1', 'Column2', or 'Column3' that corresponds to the MIN([Column6]) and then the column that corresponds to MAX([Column8]).

The output should be exactly the same except there will be an extra 2 column at the end specifying which one the min and max are associated with.

Answer 1

I think there is a simple problem in your question, as Col1,Col2,Col3 that correspond to the max or min, are displayed directly, in other words you have them as you are grouping by Col1,Col2,Col3 & Col4. As you did not provide some data, I will set some random data to prove my point. Lets create a memory table similar to yours with 9 columns and fill it with random data for col6-8 with 10 rows for example, you can use the below:-

Declare @data Table(
Column1 int,Column2 int,Column3 int,Column4 int,Column5 int,Column6 int,Column7 int,Column8 int,Column9 int
)
declare @index int=5
while(@index>0)
begin
    insert into @data values(1,2,3,4,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000)
    insert into @data values(5,6,7,8,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000)
    set @index=@index-1
end

we can see the data with the below

select * from @data  order BY [Column1],[Column2],[Column3],[Column4]

Column1 Column2 Column3 Column4 Column5 Column6 Column7 Column8 Column9
1   2   3   4   669 203 278 364 577
1   2   3   4   389 316 290 548 661
1   2   3   4   835 555 942 985 604
1   2   3   4   477 743 580 305 414
1   2   3   4   431 296 471 150 352
1   2   3   4   346 220 573 941 633
1   2   3   4   392 450 652 978 883
1   2   3   4   235 479 751 136 978
1   2   3   4   906 183 141 915 783
1   2   3   4   329 342 682 977 870
5   6   7   8   218 740 41  299 816
5   6   7   8   800 630 674 888 799
5   6   7   8   27  307 446 743 345
5   6   7   8   501 928 824 592 691
5   6   7   8   439 624 260 757 547
5   6   7   8   287 610 287 708 652
5   6   7   8   441 711 433 642 343
5   6   7   8   751 928 237 53  535
5   6   7   8   594 768 708 173 33
5   6   7   8   352 703 943 867 661

now lets see the result of your grouping that you provided without any change

Col1    Col2    Col3    Col4    minCol5 maxCol6 maxCol8 sumCol7 sumCol8 sumCol9
  1      2       3       4        235   743      985     5360    6299    6755
  5      6       7       8        27    928      888     4853    5722    5422

so if we go back to your question, what is the value of Col1,Col2,Col3 for the maxCol6, well for each maxCol6 you have the values of Col1,Col2,Col3 & even Col4. so what are the values for Col1,Col2,Col3 for maxCol16 that is 928, well they are 5,6 & 7.

ok, now lets say you want the record key that have that maxCol6, that is easy too, we would add an identity col as ID as below:-

Declare @data Table(
ID int identity(1,1), Column1 int,Column2 int,Column3 int,Column4 int,Column5 int,Column6 int,Column7 int,Column8 int,Column9 int
)
declare @index int=10
while(@index>0)
begin
    insert into @data values(1,2,3,4,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000)
    insert into @data values(5,6,7,8,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000,RAND()*1000)
    set @index=@index-1
end
select * from @data  order BY [Column1],[Column2],[Column3],[Column4]

;with agg as (
    SELECT 
           [Column1]
          ,[Column2]
          ,[Column3]
          ,[Column4]
          ,MIN([Column5]) AS minColumn5
          ,MAX([Column6]) AS maxColumn6
          ,MAX([Column8]) AS maxColumn8
          ,SUM([Column7]) AS sumColumn7
          ,SUM([Column8]) AS sumColumn8
          ,SUM([Column9]) AS sumColumn9
    FROM 
       @data [tableName]
    GROUP BY 
            [Column1]
           ,[Column2]
           ,[Column3]
           ,[Column4]

)
--select * from agg order BY [Column1],[Column2],[Column3],[Column4]
select agg.*,maxCol6.ID [MaxCol6Seq],maxCol8.ID [MaxCol8Seq]  from agg 
    inner join @data maxCol6
        on      agg.Column1=maxCol6.Column1 
            and agg.Column2=maxCol6.Column2
            and agg.Column3=maxCol6.Column3 
            and agg.Column4=maxCol6.Column4 
            and agg.maxColumn6=maxCol6.Column6
    inner join @data maxCol8
        on      agg.Column1=maxCol8.Column1 
            and agg.Column2=maxCol8.Column2
            and agg.Column3=maxCol8.Column3 
            and agg.Column4=maxCol8.Column4 
            and agg.maxColumn8=maxCol8.Column8

As this is a new run for this set of data , below:-

ID  Column1 Column2 Column3 Column4 Column5 Column6 Column7 Column8 Column9
1   1   2   3   4   201 848 993 50  304
3   1   2   3   4   497 207 644 399 104
5   1   2   3   4   445 321 822 151 185
7   1   2   3   4   611 402 620 61  543
9   1   2   3   4   460 409 182 915 211
11  1   2   3   4   886 804 180 213 282
13  1   2   3   4   614 709 932 806 162
15  1   2   3   4   795 752 110 474 463
17  1   2   3   4   737 545 77  648 727
19  1   2   3   4   788 862 266 464 851
20  5   6   7   8   218 561 943 572 54
18  5   6   7   8   741 621 610 214 536
16  5   6   7   8   579 248 374 693 761
14  5   6   7   8   866 415 198 528 657
12  5   6   7   8   905 947 500 50  387
10  5   6   7   8   492 860 948 299 220
8   5   6   7   8   861 328 727 40  327
6   5   6   7   8   435 534 707 769 777
4   5   6   7   8   587 68  45  184 614
2   5   6   7   8   189 24  289 121 772

The result is as below:-

C1  C2  C3  C4  minC5   maxC6   maxC8   sumC7   sumC8   sumC9   MaxCol6Seq  MaxCol8Seq
1   2   3   4   201      862    915      4826   4181    3832    19           9
5   6   7   8   189      947    769      5341   3470    5105    12           6

Hope this helps.

Answer 2

If you just want a flag on each row specifying whether the value is the overall maximum or minimum, you can use window functions and CASE :

SELECT [Column1], [Column2], [Column3], [Column4],
       MAX([Column5]) AS maxColumn5,
       MIN([Column6]) AS minColumn6,
       SUM([Column7]) AS sumColumn7,
       SUM([Column8]) AS sumColumn8,
       SUM([Column9]) AS sumColumn9,
       (CASE WHEN MIN([Column6]) = MIN(MIN([Column6])) OVER () THEN 1 ELSE 0 END) as is_min_column6,
       (CASE WHEN MAX([Column7]) = MAX(MAX([Column7])) OVER () THEN 1 ELSE 0 END) as is_max_column7
FROM [tableName]
GROUP BY [Column1], [Column2], [Column3], [Column4]