Как заполнить столбцы, а также строки?

Question

listagg работает, как ожидается, для poll_id=2.

Как я могу использовать то же самое для одной строки и нескольких столбцов?

with list_of_fruits as 
(select 1 as poll_id ,'Apple' as first_choice, 'Pear' as second_choice, 'Peach' as third_choice, 'Plum' as fourth_choice from dual union all 
select 2 as poll_id ,'Cherry' as first_choice, null as second_choice, null as third_choice, null as fourth_choice from dual union all 
select 2 as poll_id ,'Grape' as first_choice, null as second_choice, null as third_choice, null as fourth_choice from dual union all 
select 2 as poll_id ,'Kiwi' as first_choice, null as second_choice, null as third_choice, null as fourth_choice from dual union all 
select 3 as poll_id ,'Squash' as first_choice, 'Peas' as second_choice, '' as third_choice, null as fourth_choice from dual union all 
select 3 as poll_id ,null as first_choice, null as second_choice, null as third_choice, 'Barley' as fourth_choice from dual union all 
select 3 as poll_id ,null as first_choice, null as second_choice, 'Oats' as third_choice, null as fourth_choice from dual 

) select poll_id, listagg(first_choice,';') within group (order by poll_id) as sam 
    from list_of_fruits 
    group by poll_id 

Желаемая Выход

Consolodate все строки и столбцы (слева направо, сверху вниз), так что каждый poll_id имеет только одну строку в наборе результатов. Я хочу игнорировать нули.

1 Apple;Pear;Peach;Plum 
2 Cherry;Grape;Kiwi 
3 Squash;Peas;Barley;Oats 

Answer 1

with 
    list_of_fruits 
      (poll_id, first_choice, second_choice, third_choice, fourth_choice) as (
     select 1,'Apple' , 'Pear', 'Peach', 'Plum' from dual union all 
     select 2,'Cherry', '' , ''  , ''  from dual union all 
     select 2,'Grape' , '' , 'Berry', ''  from dual union all 
     select 2,'Kiwi' , '' , ''  , ''  from dual union all 
     select 3,'Squash', 'Peas', ''  , ''  from dual union all 
     select 3,''  , '' , ''  , 'Barley' from dual union all 
     select 3,''  , '' , 'Oats' , ''  from dual 
    ), 
    prep (poll_id, first_choice, second_choice, third_choice, fourth_choice, rn) as (
     select poll_id, first_choice, second_choice, third_choice, fourth_choice, 
       row_number() over (partition by poll_id order by null) 
     from list_of_fruits 
    ) 
select poll_id, listagg(fruit, ',') within group (order by rn, choice) as sam 
from prep 
unpivot (fruit for choice in (first_choice as 1, second_choice as 2, 
              third_choice as 3, fourth_choice as 4)) 
group by poll_id 
order by poll_id -- ORDER BY is optional 
; 


    POLL_ID SAM 
---------- ------------------------------ 
     1 Apple,Pear,Peach,Plum 
     2 Grape,Berry,Cherry,Kiwi 
     3 Squash,Peas,Barley,Oats