sql group by function

Question

I need to only get the line with the highest transactiontime per productId. So In this case I need to get the first line and all the other lines with productid 224 should be gon

Answer 1

You could do:

SELECT  MT.NQ, MT.ProductId, MT.Product, MT.Warehouse, MT.ProductType, MT.Transactiontime
FROM    @MaxTime MT
INNER JOIN (
                SELECT  ProductId
                ,       MAX(Transactiontime) AS 'TransactionTime'
                FROM    @MaxTime
                GROUP BY Productid
            ) GR
        ON  MT.ProductId = GR.ProductId
        AND MT.TransactionTime = GR.TransactionTime
ORDER BY MT.ProductId