select AlphaKey
from (
	select row_number() over(partition by AlphaKey order by AlphaKey) rownum, 
	AlphaKey 
	from @AlphaList 
) al
where rownum = 1	
order by 1;

select
	a.ProductID
	,a.UnitPrice
from
	(select
		ProductID
		,UnitPrice
		,Rank() over (order by ProductID) as Ranking
		,Row_Number() over (order by ProductID,UnitPrice) as RowNumber
	from
		[Order Details]
	) as a
where
	a.Ranking=a.RowNumber
order by
	a.ProductID

select
	a.ProductID
	,a.UnitPrice
from
	(select
		ProductID
		,UnitPrice
		,Row_Number() over (partition by ProductID order by UnitPrice) as RowNumber
	from
		[Order Details]
	) as a
where
	a.RowNumber=1
order by
	a.ProductID

select
	a.ProductID
	,a.UnitPrice
	,b.CustomerID
	,b.OrderDate
from
	(select
		ProductID
		,UnitPrice
		,OrderID
		,Row_Number() over (partition by ProductID order by UnitPrice) as RowNumber
	from
		[Order Details]
	) as a
		inner join
	Orders as b
		on
			a.OrderID=b.OrderID
where
	a.RowNumber=1
order by
	a.ProductID

declare @TempTable table (itemnumber int, unitprice decimal(18, 2));

insert into @TempTable values
(777, 10.10), 
(777, 11.11),
(777, 12.12),
(888, 13.13),
(888, 14.14),
(888, 15.15),
(999, 16.16),
(999, 17.17),
(999, 18.18);

with GetMissingItems(Rank, RowNumber, ItemNumber, UnitCost) as
(
	select
		RANK() over (order by ItemNumber) as Rank,
		ROW_NUMBER() over (order by ItemNumber) as RowNumber,
		itemnumber,
		unitprice
	from @TempTable		
) select * from GetMissingItems
where Rank = RowNumber;

select
	a.ProductID
	,a.UnitPrice
	,a.Quantity
	,a.Discount
from
	(select
		ProductID
		,UnitPrice
		,Quantity
		,Discount
		,Rank() over (order by ProductID,UnitPrice,Quantity,Discount) as Ranking
		,Row_Number() over (order by ProductID,UnitPrice,Quantity,Discount) as RowNumber
	from
		[Order Details]
	) as a
where
	a.Ranking=a.RowNumber

select
	a.ProductID
	,a.UnitPrice
	,a.Quantity
	,a.Discount
from
	(select
		ProductID
		,UnitPrice
		,Quantity
		,Discount
		,Row_Number() over (partition by ProductID,UnitPrice,Quantity,Discount order by ProductID) as RowNumber
	from
		[Order Details]
	) as a
where
	a.RowNumber=1

select
	ProductID
	,UnitPrice
	,Quantity
	,Discount
from
	[Order Details]
group by
	ProductID
	,UnitPrice
	,Quantity
	,Discount