SSRS 2005 find name of column with max value

问题:

The column on the far right is what I'm trying to add to my report. Is this possible to do without modifying the query to use something like Unpivot?

Step X      Step W      Step A     Step B     Step Y     Last Step
---------------------------------------------------------------------
1/21/2013   1/24/2013   1/3/2013   1/5/2013   1/7/2013   Step W

This is a step in the right direction, but it appears to only work in SSRS 2008: http://www.bigator.com/2012/04/26/spothighlight-minimum-and-maximum-values-in-each-row-in-matrix-report-in-ssrs/

回答1:

You can use the UNPIVOT function and a CROSS APPLY to get this:

;with cte as
(
  select col, value
  from yourtable
  unpivot
  (
    value
    for col in ([Step X], [Step W], [Step A], [Step B], [Step Y])
  ) unpiv
) 
select [Step X], 
  [Step W], 
  [Step A], 
  [Step B], 
  [Step Y],
  d.col LastStep
from yourtable
cross apply
(
  select c1.col
  from cte c1
  inner join
  (
    select max(value) MaxDate
    from cte
  ) c2
    on c1.value = c2.maxdate
) d

See SQL Fiddle with Demo