Sql 用几个标准从Oracle表中推断结果

这是一个艰难的过程。我读过关于从表中的多个行合并值的内容，但找不到任何关于如何执行我面前的任务集的内容。 我不是甲骨文人，直到现在我只做了简单的select查询，所以我在这里不知所措

在包含实验室结果的巨大oracle数据库表（severel数亿行）中，我需要选择满足特定条件的特定申请的信息

with req
AS
 (
   select reqno from t where ana IN ('A','B','C') 
    GROUP BY reqno HAVING
   count(DISTINCT  ana) = 3
 )
select * FROM
(
  select * from t where 
    exists ( select 1 from req r where t.reqno = r.reqno )
 )
    PIVOT(
          min(answer) for ana in ('A' as A, 'B' as B, 'C' as C,
                                  'X' as X, 'Y' as Y, 'Z' as Z)
           ) ORDER BY reqno;

标准：对于同一需求编号，分析A、B和C必须有答案，如果有，则应选择分析X、Y或Z答案的任何实例

附表内容：

ReqNo   Ana Answer
1       A   7
1       B   14
1       C   18
1       X   250
2       A   8
2       X   35
2       Y   125
3       A   8
3       B   16
3       C   20
3       Z   100
4       X   115
4       Y   355
5       A   6
5       B   15
5       C   22
5       X   300
5       Y   108
5       C   88

预期结果：

ReqNo   A   B   C   X   Y   Z
1      7    14  18  250     
3      8    16  20          100
5      6    15  22  300 108 88

遗漏需求2和需求4，因为它们不符合A/B/C标准

with req
AS
 (
   select reqno from t where ana IN ('A','B','C') 
    GROUP BY reqno HAVING
   count(DISTINCT  ana) = 3
 )
select * FROM
(
  select * from t where 
    exists ( select 1 from req r where t.reqno = r.reqno )
 )
    PIVOT(
          min(answer) for ana in ('A' as A, 'B' as B, 'C' as C,
                                  'X' as X, 'Y' as Y, 'Z' as Z)
           ) ORDER BY reqno;

---

这是可能的吗？

您可以首先筛选包含所有3个（A、B和C）的记录，然后使用

PIVOT

将它们转换为满足条件的列

with req
AS
 (
   select reqno from t where ana IN ('A','B','C') 
    GROUP BY reqno HAVING
   count(DISTINCT  ana) = 3
 )
select * FROM
(
  select * from t where 
    exists ( select 1 from req r where t.reqno = r.reqno )
 )
    PIVOT(
          min(answer) for ana in ('A' as A, 'B' as B, 'C' as C,
                                  'X' as X, 'Y' as Y, 'Z' as Z)
           ) ORDER BY reqno;

---

您可以首先筛选包含所有3个（A、B和C）的记录，然后使用

PIVOT

将它们转换为满足条件的列

with req
AS
 (
   select reqno from t where ana IN ('A','B','C') 
    GROUP BY reqno HAVING
   count(DISTINCT  ana) = 3
 )
select * FROM
(
  select * from t where 
    exists ( select 1 from req r where t.reqno = r.reqno )
 )
    PIVOT(
          min(answer) for ana in ('A' as A, 'B' as B, 'C' as C,
                                  'X' as X, 'Y' as Y, 'Z' as Z)
           ) ORDER BY reqno;

---

我只想使用条件聚合：

select reqno,
       max(case when Ana = 'A' then Answer end) as a,
       max(case when Ana = 'B' then Answer end) as b,
       max(case when Ana = 'C' then Answer end) as c,
       max(case when Ana = 'X' then Answer end) as x,
       max(case when Ana = 'Y' then Answer end) as y,
       max(case when Ana = 'Z' then Answer end) as z
from t
group by reqno
having sum(case when Ana = 'A' then 1 else 0 end) > 0 and
       sum(case when Ana = 'B' then 1 else 0 end) > 0 and
       sum(case when Ana = 'C' then 1 else 0 end) > 0 ;

考虑到您似乎没有重复项，您可以将

拥有

简化为：

having sum(case when Ana in ('A', 'B', 'C') then 1 else 0 end) = 3

---

我只想使用条件聚合：

select reqno,
       max(case when Ana = 'A' then Answer end) as a,
       max(case when Ana = 'B' then Answer end) as b,
       max(case when Ana = 'C' then Answer end) as c,
       max(case when Ana = 'X' then Answer end) as x,
       max(case when Ana = 'Y' then Answer end) as y,
       max(case when Ana = 'Z' then Answer end) as z
from t
group by reqno
having sum(case when Ana = 'A' then 1 else 0 end) > 0 and
       sum(case when Ana = 'B' then 1 else 0 end) > 0 and
       sum(case when Ana = 'C' then 1 else 0 end) > 0 ;

考虑到您似乎没有重复项，您可以将

拥有

简化为：

having sum(case when Ana in ('A', 'B', 'C') then 1 else 0 end) = 3