Merge into item_TMP S using items I on (S.ITL_ITEM= I.ITEM_ITEM) 
when matched then
update set 
S.ITL_UOM = I.ITEM_UOM; 
when not matched then  null;

تم تعديل 3 مايو 200916 سنة بواسطة new_world

شكرا ياشباب
الحمد لله وصلت للحل وبطريقتين

update item_TMP set ITL_UOM = (select ITEM_UOM from ITEMS where item_TMP.ITL_ITEM = ITEMS.ITEM_ITEM and items.ITEM_UOM is not null )
where ITL_ITEM in (select  ITEMS.ITEM_ITEM from ITEMS where items.ITEM_UOM is not null )

Merge into item_TMP S using items I on (S.ITL_ITEM= I.ITEM_ITEM) 
when matched then
update set 
S.ITL_UOM = I.ITEM_UOM;