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 use a CTE, so that you ensure you get the NQ from the same row as the TransactionTime, e.g.:

;WITH Data AS (
    SELECT      NQ, 
                ProductId, 
                Product, 
                Warehouse, 
                ProductType, 
                TransactionTime,
                ROW_NUMBER() OVER (PARTITION BY Productid, Product, Warehouse, ProductType ORDER BY TransactionTime DESC) AS rn

    FROM        @MaxTime
)
SELECT      NQ, 
            ProductId, 
            Product, 
            Warehouse, 
            ProductType, 
            TransactionTime

FROM        Data

WHERE       rn = 1

ORDER BY    ProductId