Question

Using SQL Server 2005, I am attempting to write a select statement which will query the data below (18000 rows) and return one row per Product, finding the largest product version.

I think the query needs to compare the versions in reverse, and storing the largest row number as it gets up to Major but I am not sure.

Sample Data

    Product  Date       Major  Minor  Release Fixpack Build
    =======  ========== ====== ====== ======  ======  ======
    Widgets  01/01/2012 10     1      0       345     132
    Widgets  04/02/2011 6      6      3       932     245
    Widgets  09/01/2010 4      92     345     53      2
    Gears    03/17/2011 9      2      3       0       21
    Gears    12/12/2012 10     0      0       5       548
    Tires    04/24/2000 8      3      456     3       984
    Tires    04/12/1993 7      14     45      35      252

Expected Results

    Product  Date       Major  Minor  Release Fixpack Build
    =======  ========== ====== ====== ======  ======  ======
    Widgets  01/01/2012 10     1      0       345     132
    Gears    12/12/2012 10     0      0       5       548
    Tires    04/24/2000 8      3      456     3       984

OR even better, could combine the versions into one column:

    Product  Date       ProductVersion
    =======  ========== ==================
    Widgets  01/01/2012 10.1.0.345.132
    Gears    12/12/2012 10.0.0.5.548
    Tires    04/24/2000 8.3.456.3.984

Answer 1

You can use the ROW_NUMBER function in a derived table. Do the partition on Product and order by Date desc or your version information.

Ordered by Date desc:

select T.Product,
       T.Date,
       T.ProductVersion
from (
     select Product,
            Date,
            cast(Major as varchar(5))+'.'+
            cast(Minor as varchar(5))+'.'+
            cast(Release as varchar(5))+'.'+
            cast(Fixpack as varchar(5))+'.'+
            cast(Build as varchar(5)) as ProductVersion,
            row_number() over(partition by Product order by Date desc) as rn
     from YourTable
     ) as T
where T.rn = 1

Ordered by ProductVersion desc

select T.Product,
       T.Date,
       T.ProductVersion
from (
     select Product,
            Date,
            cast(Major as varchar(5))+'.'+
            cast(Minor as varchar(5))+'.'+
            cast(Release as varchar(5))+'.'+
            cast(Fixpack as varchar(5))+'.'+
            cast(Build as varchar(5)) as ProductVersion,
            row_number() over(partition by Product 
                              order by Major desc, 
                                       Minor desc, 
                                       Release desc, 
                                       Fixpack desc, 
                                       Build desc) as rn
     from YourTable
     ) as T
where T.rn = 1

SQL Fiddle