在Oracle SQL中将多行分组为一行

如何使图1中的数据集看起来像图2中的数据。基本上，我不想把每次购买都放在自己的线上，而是想按姓名分组，让所有的人都在一条线上购买。他们最多可以购买5件物品，我的数据库中大约有3000万行物品

另外，日期顺序并不重要

您可以使用行数和条件聚合：

select name,
       max(case when seqnum = 1 then item end) as item_1,
       max(case when seqnum = 1 then date end) as date_1,
       max(case when seqnum = 2 then item end) as item_2,
       max(case when seqnum = 2 then date end) as date_2,
       max(case when seqnum = 3 then item end) as item_3,
       max(case when seqnum = 3 then date end) as date_3
from (select t.*,
             row_number() over (partition by name order by date asc) as seqnum
      from t
     ) t
group by name;

您可以使用行数和条件聚合：

select name,
       max(case when seqnum = 1 then item end) as item_1,
       max(case when seqnum = 1 then date end) as date_1,
       max(case when seqnum = 2 then item end) as item_2,
       max(case when seqnum = 2 then date end) as date_2,
       max(case when seqnum = 3 then item end) as item_3,
       max(case when seqnum = 3 then date end) as date_3
from (select t.*,
             row_number() over (partition by name order by date asc) as seqnum
      from t
     ) t
group by name;

您可以使用具有行号的轴，如下所示：

Select * from 
   (select t.*,
           row_number() over (partition by name order by date_purchased) rn
      from your_table t
  ) PIVOT
(Max(item_purchased), max(date_purchased) For rn in (1,2,3));

您可以使用具有行号的轴，如下所示：

Select * from 
   (select t.*,
           row_number() over (partition by name order by date_purchased) rn
      from your_table t
  ) PIVOT
(Max(item_purchased), max(date_purchased) For rn in (1,2,3));