Oracle中如何将两行或多行转换为列

Question

我有一个表映射，它具有如下所示的列名和值。 （我有超过 20 列）。

Original Data

我想把它转换成：

(0/NULL) Final Result

谁能帮帮忙。

我已经编写了以下查询，该查询仅适用于一列，但如何为超过两列执行此操作？

从 cte3 中选择 * 枢（ min(1) for column1 in ( a , b , c , d ) ) 按id排序

Answer 1

您需要使用条件聚合，因为PIVOT无法处理。

SQL> WITH CTE(ID,COLUMN1,COLUMN2,COLUMN3,COLUMN4) AS
  2  (SELECT 1,'A','E','I','M' FROM DUAL UNION ALL
  3  SELECT 2,'B','F','J','N' FROM DUAL UNION ALL
  4  SELECT 3,'C','G','K','O' FROM DUAL UNION ALL
  5  SELECT 4,'D','H','L','P' FROM DUAL)
  6  --your query starts from here
  7  SELECT ID,
  8         COALESCE(SUM(CASE WHEN 'A' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS A,
  9         COALESCE(SUM(CASE WHEN 'B' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS B,
 10         COALESCE(SUM(CASE WHEN 'C' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS C,
 11         COALESCE(SUM(CASE WHEN 'D' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS D,
 12         COALESCE(SUM(CASE WHEN 'E' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS E,
 13         COALESCE(SUM(CASE WHEN 'F' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS F,
 14         COALESCE(SUM(CASE WHEN 'G' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS G,
 15         COALESCE(SUM(CASE WHEN 'H' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS H,
 16         COALESCE(SUM(CASE WHEN 'I' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS I,
 17         COALESCE(SUM(CASE WHEN 'J' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS J,
 18         COALESCE(SUM(CASE WHEN 'K' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS K,
 19         COALESCE(SUM(CASE WHEN 'L' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS L,
 20         COALESCE(SUM(CASE WHEN 'M' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS M,
 21         COALESCE(SUM(CASE WHEN 'N' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS N,
 22         COALESCE(SUM(CASE WHEN 'O' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS O,
 23         COALESCE(SUM(CASE WHEN 'P' IN (COLUMN1,COLUMN2,COLUMN3,COLUMN4) THEN 1 END),0) AS P
 24    FROM CTE
 25  GROUP BY ID;

        ID  A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P
---------- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
         1  1  0  0  0  1  0  0  0  1  0  0  0  1  0  0  0
         2  0  1  0  0  0  1  0  0  0  1  0  0  0  1  0  0
         4  0  0  0  1  0  0  0  1  0  0  0  1  0  0  0  1
         3  0  0  1  0  0  0  1  0  0  0  1  0  0  0  1  0

SQL>

Answer 2

with q1 as (
select 1 id, 'A' column1, 'E' column2, 'I' column3, 'M' column4 from dual
union all
select 2 id, 'B' column1, 'F' column2, 'J' column3, 'N' column4 from dual
union all
select 3 id, 'C' column1, 'G' column2, 'K' column3, 'O' column4 from dual
union all
select 4 id, 'D' column1, 'H' column2, 'L' column3, 'P' column4 from dual
),
--select * from q1;
q2 as (
select 
   id,
   column1 as c1, case when column1 in ('A','B','C','D') then id end as c1p,
   column2 as c2, case when column2 in ('E','F','G','H') then 4+id end as c2p,
   column3 as c3, case when column3 in ('I','J','K','L') then 8+id end as c3p,
   column4 as c4, case when column4 in ('M','N','O','P') then 12+id end as c4p
from q1
order by 1
),
--select * from q2;
q3 as (
select id, c1p as pos, c1 as val from q2
union all
select id, c2p as pos, c2 as val from q2
union all
select id, c3p as pos, c3 as val from q2
union all
select id, c4p as pos, c4 as val from q2
order by 1,2
),
--select * from q3;
q4 as (
select distinct pos, val from q3 order by 1
),
--select * from q4;
q5 as (
select q3.id, q4.pos, q4.val, case when q3.val = q4.val then 1 else 0 end as nval
from q3 
partition by (q3.id)
right outer join q4
on (q3.pos = q4.pos)
order by 1,2
)
--select * from q5;
select 
   id, 
   sum(A) as A, sum(B) as B, sum(C) as C, sum(D) as D,
   sum(E) as E, sum(F) as F, sum(G) as G, sum(H) as H,
   sum(I) as I, sum(J) as J, sum(K) as K, sum(L) as L,
   sum(M) as M, sum(N) as N, sum(O) as O, sum(P) as P
from q5
pivot ( sum(nval) for val in (   
           'A' as A,'B' as B,'C' as C,'D' as D,
           'E' as E,'F' as F,'G' as G,'H' as H,
           'I' as I,'J' as J,'K' as K,'L' as L,
           'M' as M,'N' as N,'O' as O,'P' as P
        )
)
group by id
order by 1
;

Snapshot of Results as expected