select      customer_id

           ,split
            (
                regexp_replace
                (
                    concat(ItemListB,',:,',ItemListA)
                   ,'(?<=^|,)(?<item>.*?),(?=.*(?<=,)\\k<item>(?=,|$))'
                   ,''
                )
               ,',?:'
            )[0]        as ItemListB_A

from        mytable

+-------------+-------------+
| customer_id | itemlistb_a |
+-------------+-------------+
|          24 | 4,5         |
|          26 | 8,9,10      |
|          25 | 8           |
+-------------+-------------+

这将得到预期的结果。

select Customer_id, collect_list(y) from
    (select Customer_id, y , count(*) as cnt from 
    (select Customer_id,y from (select Customer_id, split(concat_ws(',',ItemListA,ItemListB),',') as x from table_name) temp lateral view explode(x) temp as y) temp1 
    group by Customer_id,y  ) temp2 where cnt =1 group by Customer_id;

select a.Customer_id,concat_ws (',',collect_list (a.item)) as ItemListB_A from (            
select      t.Customer_id
                       ,pe.item

            from        test_hive     t
                        lateral view posexplode (split (concat_ws(',',ItemListB),',')) pe as pos,item
                        lateral view posexplode (split (concat_ws(',',ItemListA),',')) pe1 as pos1,item1
            group by t.Customer_id,pe.item
            having count(case when item=item1 then 1 end)=0
)a
group by a.Customer_id

select      customer_id
           ,concat_ws (',',collect_list (item)) as ItemListB_A

from       (select      t.customer_id
                       ,pe.item

            from        mytable     t
                        lateral view posexplode (split (concat_ws(',',ItemListA,ItemListB),',')) pe as pos,item

            group by    t.customer_id
                       ,pe.item

            having      count (case when pos < size(split(ItemListA,',')) then 1 end) = 0  
            ) t

group by    customer_id

+-------------+-------------+
| customer_id | itemlistb_a |
+-------------+-------------+
|          24 | 4,5         |
|          25 | 8           |
|          26 | 10,8,9      |
+-------------+-------------+