[SOLVED] Return latest price per product

Return latest price per product - SQL

I am an SQL Noob and have been thrown in at the deep end it feels, I have been asked to pull some data from a DB using an existing script. I need to modify the script such that I pull the product info using the latest price for each product. Having done some reading I believe I need to use a nested select statement to pull the max month per product to get the latest price but I am unsure as to how to incorporate it into my script.

Currently the DB is returning the following format:

Fill Month  ProdName1   ProdName2   PackType    Quantity    Prod Cost
  2018/01   ProdA        ProdA_ALT  Pack1         30          7.35
  2018/02   ProdB        ProdB_ALT  Pack5         60          6.68
  2018/01   ProdE        ProdE_ALT  Pack2         54538      81010.86
  2018/03   ProdA        ProdA_ALT  Pack1         600         97.22
  2018/01   ProdC        ProdC_ALT  Pack2         1230       30192.25
  2018/05   ProdD        ProdD_ALT  Pack4         60262      51396.6
  2018/01   ProdF        ProdF_ALT  Pack3         480         109.3
  2018/07   ProdA        ProdA_ALT  Pack1         210         149.94
  2018/09   ProdF        ProdF_ALT  Pack3         360         26.68
  2018/10   ProdD        ProdD_ALT  Pack4         9585        14350.47

But what I wish to return are rows # 2,3,5,8,9,10 since these are the latest prices based on date for each of the products.

My SQL query looks as follows:

SELECT               
        table1.month AS 'Fill Month',
        table2.field2 AS PackType,
        TRIM(table2.brand) ProdName1,
        TRIM(table2.field3) ProdName2,
        SUM(table3.field4) 'Fill Qty',
        SUM(table3.field5) 'Calc Cost'

FROM
        DB_Name.overseas.CLAIMINFO table3
        INNER JOIN DB_Name.overseas.DIM1 table1
        ON table3.key1 = table1.key1
        INNER JOIN DB_Name.overseas.DIM2 table2
        ON table3.key2 = table2.key2
        INNER JOIN DB_Name.overseas.DIM3 table4 
        ON table3.key3 = table4.key3
        INNER JOIN DB_Name.overseas.DIM4 table5
        ON table3.key4 = table5.key4
        INNER JOIN DB_Name.overseas.DIM5 table6
        ON table3.key5 = table6.key5 
        INNER JOIN DB_Name.overseas.LOOKUP table7
        ON table3.key6 = table7.key6
        INNER JOIN DB_Name.overseas.DIM6 table8
    ON table3.key7 = table8.key7
    INNER JOIN DB_Name.overseas.LOOKUP_key8 table9
        ON table3.key8 = table9.key8

WHERE
        table1.day BETWEEN '2018-01-01' AND '2018-08-31'  --TIME PERIOD
        AND (table2.brand LIKE '%PRODA%' OR table2.brand LIKE '%PRODUCTB%'
                                            OR table2.brand LIKE '%PRODC%'
                                            OR table2.brand LIKE '%PRODD%'
                                            OR table2.brand LIKE '%PRODE%'
                                            OR table2.brand LIKE '%PRODF%'
        AND LEFT(table3.account_id, 1) <> 'E' 
        AND grp1.grp_nbr NOT IN ('12345', '67890')

GROUP BY 
        table1.month,
        table2.field2,
        table2.field3,
        table2.drug_str_descr,
        dr1

I have tried using a nested SELECT just inside the first from statement but the RDBMS kicks back an error each time, if anyone has any pointers I would be very grateful.

Solution

To get the last date each product changed, try this:

(SELECT ProdName1, Max(FillMonth) 
FROM tablename
GROUP BY ProdName1) AS ProductDates

You can join to this in your FROM clause to limit the results to just the months you want.