Top 1 Item from the List in SQL - sql

Question

I have the following scenario
I am getting Output like this
Month Product Name Amount
Jan-2014 A-Prodcut 50
Jan-2014 B-Product 45
Jan-2014 C-Product 55
Feb-2014 A-Prodcut 60
Feb-2014 B-Product 48
Feb-2014 C-Product 80
I want Output like this :
Jan-2014 C-Product 55
Feb-2014 C-Product 80
I want top product from each month How to achieve this
Here is my query
;With cte as
(
SELECT #EndDate AS TheMonth, 0 as [Counter]
UNION ALL
SELECT DATEADD(mm,-[Counter] -1,#EndDate), Counter + 1 AS TheMonth
from cte
WHERE DATEADD(mm,-[Counter] -1,#EndDate) >= #StartDate
)
SELECT
left(DATENAME(MM,TheMonth),3) +'-'+ cast(year(TheMonth) as varchar) AS [Month-Year],
ISNULL(IM.product_name,'N/A') as 'Product Name',
isnull(sum((ism.selling_price * siim.qty) + (((tm.tax_amount*(ism.selling_price * siim.qty))/100))),0) AS Amount
FROM
cte
LEFT OUTER JOIN RS_Sell_Order_Master AS SM on MONTH(invoice_date) = MONTH(TheMonth)
AND YEAR(invoice_date) = YEAR(TheMonth)
AND sm.is_approved = 1
LEFT OUTER JOIN RS_Sells_Invoice_Info_Master AS SIIM ON SM.sell_order_no = SIIM.sell_order_no
LEFT OUTER JOIN RS_Inventory_Master AS IM ON SIIM.product_id = IM.product_id
LEFT OUTER JOIN RS_Tax_Master AS TM ON TM.tax_id = SIIM.tax_id
LEFT OUTER JOIN RS_Inventory_Selling_Master AS ISM ON ISM.selling_product_id = SIIM.selling_product_id
GROUP BY
IM.product_name,
TheMonth

Answer 1

Use Row_number() in the select query ie.
SELECT MONTH, PRODUCT_NAME, AMOUNT
FROM (
SELECT MONTH, PRODUCT_NAME, AMOUNT,
ROW_NUMBER ( )
OVER (PARTITION BY Month order by amount Desc) AS RANK
)
WHERE RANK = 1
Hope this helps..

Answer 2

Try this:
SELECT *
FROM
(
SELECT [Month-Year], [Product Name], Amount, ROW_NUMBER() OVER (Partition BY [Month-Year] ORDER BY Amount DESC) as rn
FROM
(
SELECT
left(DATENAME(MM,TheMonth),3) +'-'+ cast(year(TheMonth) as varchar) AS [Month-Year],
ISNULL(IM.product_name,'N/A') as 'Product Name',
isnull(sum((ism.selling_price * siim.qty) + (((tm.tax_amount*(ism.selling_price * siim.qty))/100))),0) AS Amount
FROM
cte
LEFT OUTER JOIN RS_Sell_Order_Master AS SM on MONTH(invoice_date) = MONTH(TheMonth)
AND YEAR(invoice_date) = YEAR(TheMonth)
AND sm.is_approved = 1
LEFT OUTER JOIN RS_Sells_Invoice_Info_Master AS SIIM ON SM.sell_order_no = SIIM.sell_order_no
LEFT OUTER JOIN RS_Inventory_Master AS IM ON SIIM.product_id = IM.product_id
LEFT OUTER JOIN RS_Tax_Master AS TM ON TM.tax_id = SIIM.tax_id
LEFT OUTER JOIN RS_Inventory_Selling_Master AS ISM ON ISM.selling_product_id = SIIM.selling_product_id
GROUP BY
IM.product_name,
TheMonth
) a
)b
WHERE rn = 1

Answer 3

Usually OUTER APPLY or CROSS APPLY is a way to go in theese situations.
So your SELECT would be like this:
;With cte as
(
SELECT #EndDate AS TheMonth, 0 as [Counter]
UNION ALL
SELECT DATEADD(mm,-[Counter] -1,#EndDate), Counter + 1 AS TheMonth
from cte
WHERE DATEADD(mm,-[Counter] -1,#EndDate) >= #StartDate
)
SELECT
left(DATENAME(MM,TheMonth),3) +'-'+ cast(year(TheMonth) as varchar) AS [Month-Year],
'Product Name', Amount
FROM
cte
OUTER APPLY ( SELECT TOP 1
ISNULL(IM.product_name,'N/A') as 'Product Name',
isnull(sum((ism.selling_price * siim.qty) +
(((tm.tax_amount*(ism.selling_price * siim.qty))/100))),0) AS Amount
FROM RS_Sell_Order_Master AS SM
LEFT OUTER JOIN RS_Sells_Invoice_Info_Master AS SIIM
ON SM.sell_order_no = SIIM.sell_order_no
LEFT OUTER JOIN RS_Inventory_Master AS IM
ON SIIM.product_id = IM.product_id
LEFT OUTER JOIN RS_Tax_Master AS TM
ON TM.tax_id = SIIM.tax_id
LEFT OUTER JOIN RS_Inventory_Selling_Master AS ISM
ON ISM.selling_product_id = SIIM.selling_product_id
WHERE MONTH(invoice_date) = MONTH(TheMonth) AND YEAR(invoice_date) = YEAR(TheMonth) AND sm.is_approved = 1
ORDER BY Amount DESC
) x
GROUP BY
'Product Name',
TheMonth