UPDATE `0p4_customer_group_pricing_detail` d
left join 0p4_item i on i.item_id = d.item_id
 SET d.uom_id = i.keep_stock_uom_id
WHERE customer_group_pricing_id=5


select d.uom_id as "UOM", i.uom_id as "IUOM" from `0p4_customer_group_pricing_detail` d
left join 0p4_item i on i.item_id = d.item_id

WHERE customer_group_pricing_id=5 and d.id=621
