product id            prodoctcode
1                     po1
2                     po2
3                     po3
4                     po4
5                     po5
6                     po6
7                     po7

priceid   product id              price         yearadded
1              1                     10            2018
2              1                     13            2019
3              2                     14            2015
4              2                     15            2016
5              3                     16            2019
6              4                     17            2017
7              4                     18            2015

product id            prodoctcode      price    yearadded
1                        po1              13        2019
2                        po2              15        2016
3                        po3              16        2019
4                        po4              17        2017

select a.`product id`,  a.prodoctcode, b.price, b.yearadded
from  producttable a
inner join pricetable  b on a.`product id` = b.`product id`
inner join  (
  select `product id`,  max(yearadded) year
  from pricetable
  group  by `product id`
)  t.`product id` = b.`product id` and t.year = b.yearadded

SELECT pt.`product id`,
       pt.prodoctcode,
       p.price,
       p.yearadded
FROM producttable pt
JOIN pricetable p ON pt.`product id` = p.`product id`
WHERE exists (
    SELECT 1
    FROM pricetable pp
    WHERE pp.`product id` = p.`product id`
    HAVING max(pp.yearadded) = p.yearadded
)

| product id | prodoctcode | price | yearadded |
|------------|-------------|-------|-----------|
|          1 |         po1 |    13 |      2019 |
|          2 |         po2 |    15 |      2016 |
|          3 |         po3 |    16 |      2019 |
|          4 |         po4 |    17 |      2017 |