Sql Server Displaying Items in specific order

Question

I have a list of items

ItemName Manufacturer TopSalesUnit

Item1     A             100   
Item2     A             80                      
Item3     A             60
Item4     B             70   
Item5     B             50   
Item6     B             30
Item7     C             10       
Item8     C             05

I would like the records to be ordered so that the highest TopSalesUnit item is shown first, then the next highest item from a different manufacturer is shown second, then the next highest item from a third manufacturer is shown, etc.:

ItemName Manufacturer TopSalesUnit

Item1       A             100    
Item4       B             070
Item7       C             010 
Item2       A             080
Item5       B             050 
Item8       C             005   
Item3       A             060 
Item6       B             030 

How to write a query in T-SQL to achieve it?

Answer 1

try:

DECLARE @YourTable table (ItemName varchar(10), Manufacturer char(1), TopSalesUnit int)

INSERT @YourTable VALUES ('Item1','A ',100)
INSERT @YourTable VALUES ('Item2','A ',80)                 
INSERT @YourTable VALUES ('Item3','A ',60)
INSERT @YourTable VALUES ('Item4','B ',70)   
INSERT @YourTable VALUES ('Item5','B ',50)   
INSERT @YourTable VALUES ('Item6','B ',30)
INSERT @YourTable VALUES ('Item7','C ',10)       
INSERT @YourTable VALUES ('Item8','C ',05)

SELECT
    dt.ItemName,dt.Manufacturer,dt.TopSalesUnit
    FROM (SELECT
              ItemName,Manufacturer,TopSalesUnit,ROW_NUMBER() OVER(PARTITION BY Manufacturer ORDER BY TopSalesUnit DESC) AS RowNumber
              FROM @YourTable
         ) dt 
    ORDER BY dt.RowNumber,dt.Manufacturer

OUTPUT:

ItemName   Manufacturer TopSalesUnit
---------- ------------ ------------
Item1      A            100
Item4      B            70
Item7      C            10
Item2      A            80
Item5      B            50
Item8      C            5
Item3      A            60
Item6      B            30

(8 row(s) affected)

Answer 2

Try this:

SELECT *,
    ( SELECT COUNT(*) FROM Items b
    WHERE b.Manufacturer = Items.Manufacturer
    AND b.TopSalesUnit > Items.TopSalesUnit )
    AS RankInManufacturer
FROM Items
ORDER BY RankInManufacturer, TopSalesUnit DESC

This adds a new computed column that ranks the "TopSalesUnit" fields within each "Manufacturer".