你可以用 row_number 或者 full join . 这是一个使用 row_number :

insert overwrite table_1 
select customer_id, items, price, updated_date
from
(
select customer_id, items, price, updated_date,
       row_number() over(partition by customer_id order by new_flag desc) rn
from 
    (
     select customer_id, items, price, updated_date, 0 as new_flag
       from table_1
     union all
     select customer_id, items, price, updated_date, 1 as new_flag
       from table_2
    ) all_data
)s where rn=1;

另请参阅此答案，以便使用 FULL JOIN : https://stackoverflow.com/a/37744071/2700344