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[英]Picking from a column, with different criterias, to one table - SQL Oracle
[英]Concetating results from Oracle table with several criterias
這是困難的一個。 我已經讀過關於如何從表中的多個行合並值的信息,但找不到關於如何處理擺在我面前的任務集的任何信息。 我不是一個Oracle專家,直到現在只進行了簡單的選擇查詢,所以我在這里很茫然。
在一個包含實驗室結果的巨大的oracle數據庫表(幾億行)中,我需要選擇滿足特定條件的特定請購信息。
准則:對於相同的需求編號,必須在分析AB和C中提供答案,如果存在,則應選擇分析X,Y或Z的任何答案實例
表內容:
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
所需結果:
ReqNo A B C X Y Z
1 7 14 18 250
3 8 16 20 100
5 6 15 22 300 108 88
忽略了要求2和4,因為它們不符合A / B / C標准。
那有可能嗎?
您可以首先過濾所有3個記錄(A,B和C),然后使用PIVOT
將它們轉換為滿足條件的列。
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;
我只會使用條件聚合:
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 ;
既然你似乎並不有重復,可以簡化having
到:
having sum(case when Ana in ('A', 'B', 'C') then 1 else 0 end) = 3
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