$ 0 0 Solution: update ggg_1 t1 set t1.product_from = (select product_to from ggg_1 t2 where t2.duration = t1.duration - 1) where t1.duration != 1;
Solution:
update ggg_1 t1
set t1.product_from = (select product_to
from ggg_1 t2
where t2.duration = t1.duration - 1)
where t1.duration != 1;