Question

我可以从以下位置更改选择记录的显示方式吗

Ticket   Colour
12321    Green
12321    Blue
12321    Yellow
22653    Red
22653    Black

收件人：

Ticket   Colour1   Colour2   Colour3
12321    Green     Blue      Yellow
22653    Red       Black

Answer 1

我建议在这里使用LISTAGG

 SELECT
    Ticket,
    LISTAGG(Colour, ',') WITHIN GROUP (ORDER BY Colour) AS Colours
FROM yourTable
GROUP BY Ticket;

Ticket   Colours
12321    Blue,Green,Yellow
22653    Black,Red

我建议这样做的原因是，也许您的数据集最终可能会超过3列。动态SQL可能会帮助您解决此问题，但这将需要大量工作。

Answer 2

如果需要多个列，则可以使用条件聚合：

select ticket,
       max(case when seqnum = 1 then colour end) as colour_1,
       max(case when seqnum = 2 then colour end) as colour_2,
       max(case when seqnum = 3 then colour end) as colour_3
from (select t.*,
             row_number() over (partition by ticket order by ticket) as seqnum
      from t
     ) t
group by ticket;

我应该注意，不能保证颜色的顺序。 SQL表表示 unordered 集，因此除非有另一列指定排序，否则不进行排序。

Answer 3

create table ex(
no number,
colour varchar(20));

insert into ex values(12321,    'Green');
insert into ex values(12321   , 'Blue');
insert into ex values(12321   , 'Yellow');
insert into ex values(22653   , 'Red');
insert into ex values(22653   , 'Black');
select * from ex;

SELECT LISTAGG(colour, ', ') WITHIN GROUP (ORDER BY no)
FROM ex group by no;

输出

12321   Blue, Green, Yellow
22653   Black, Red

Oracle SQL-更改记录演示

3 个答案: