转置和聚合Oracle列数据

Question

我有以下数据

Base          End
RMSA          Item 1
RMSA          Item 2
RMSA          Item 3
RMSB          Item 1
RMSB          Item 2
RMSC          Item 4

我想将其转换为以下格式

    Key           Products
    RMSA;RMSB     Item 1, Item 2
    RMSA          Item 3
    RMSC          Item 4

基本上，具有类似结果的那些应该分为1行。但是，我似乎无法使用listagg等工作，因为我正在分组两列。

有没有办法用直接的Oracle查询来做到这一点？

Answer 1

您可以使用listagg()窗口分析函数两次

with t1( Base, End ) as
( 
 select 'RMSA','Item 1' from dual union all
 select 'RMSA','Item 2' from dual union all 
 select 'RMSA','Item 3' from dual union all
 select 'RMSB','Item 1' from dual union all
 select 'RMSB','Item 2' from dual union all
 select 'RMSC','Item 4' from dual 
),
   t2 as
(   
select 
       listagg(base,';') within group (order by end) 
       as key,
          end   
  from t1
 group by end 
)
select key, 
       listagg(end,',') within group (order by end) 
       as Products
  from t2  
 group by key
 order by products;

Key           Products
---------     --------------
RMSA;RMSB     Item 1, Item 2
RMSA          Item 3
RMSC          Item 4  

Demo

Answer 2

以下是一种方式 -

WITH base 
     AS (SELECT 'RMSA'   AS base, 
                'Item 1' AS end1 
         FROM   dual 
         UNION 
         SELECT 'RMSA'   AS base, 
                'Item 2' AS end1 
         FROM   dual 
         UNION 
         SELECT 'RMSA'   AS base, 
                'Item 3' AS end1 
         FROM   dual 
         UNION 
         SELECT 'RMSB'   AS base, 
                'Item 1' AS end1 
         FROM   dual 
         UNION 
         SELECT 'RMSB'   AS base, 
                'Item 2' AS end1 
         FROM   dual 
         UNION 
         SELECT 'RMSC'   AS base, 
                'Item 4' AS end1 
         FROM   dual), 
     t11 
     AS (SELECT t1.base base1, 
                t1.end1 AS end11, 
                t2.base base2, 
                t2.end1 AS end12 
         FROM   base t1 
                inner join base t2 
                        ON t1.end1 = t2.end1 
         WHERE  t1.base > t2.base) SELECT 
Concat(Concat(t11.base1, ';'), t11.base1), 
       Listagg(t11.end11, ',') 
         within GROUP (ORDER BY t11.end11) 
FROM   t11 
GROUP  BY Concat(Concat(t11.base1, ';'), t11.base1) 
--above query will get you results where you have similar results 
UNION 
SELECT t1.base, 
       t1.end1 
FROM   base t1 
       left outer join t11 
                    ON t1.base = t11.base1 
                       AND t1.end1 = t11.end11 
       left outer join t11 t12 
                    ON t1.base = t12.base2 
                       AND t1.end1 = t12.end11 
WHERE  t11.base1 IS NULL 
       AND t12.base2 IS NULL; 

希望这可以帮助