計數值逗號分隔

Question

我有下表：

A   V
-   -
A1  B, C
A2  C, 2W
A3  D
A4  10K, 10W, 2A

我想計算 V 中的值並按出現順序排列它們。 預期 output：

O  COUNT(*)
-  -------
W       12
K       10
A        2
C        2
B        1
D        1

Answer 1

您可以使用REGEX_SUBSTR()和REGEXP_REPLACE()函數的組合以及分層查詢，假設所有以逗號分隔的元素，無論何時修剪空格，都是正數 integer + 一個字母的形式，例如

WITH t2 AS
(
 SELECT TRIM(REGEXP_SUBSTR(v,'[^,]+',1,level)) AS v
   FROM t 
CONNECT BY level <= REGEXP_COUNT(v,',')+1
    AND PRIOR SYS_GUID() IS NOT NULL
    AND PRIOR a = a
)
SELECT NVL(SUM(REGEXP_REPLACE(v,'[^[:digit:]]')),
           CASE WHEN COUNT(*)>1 THEN COUNT(*) END)||REGEXP_REPLACE(v,'[^[:alpha:]]') AS o
  FROM t2 
 GROUP BY REGEXP_REPLACE(v,'[^[:alpha:]]')    

演示

編輯（取決於問題的最后編輯）：只需刪除連接運算符，並以COUNT聚合為條件，例如

SELECT REGEXP_REPLACE(v,'[^[:alpha:]]') AS o,
       NVL(SUM(REGEXP_REPLACE(v,'[^[:digit:]]')),COUNT(*)) AS count 
  FROM t2 
 GROUP BY REGEXP_REPLACE(v,'[^[:alpha:]]') 
 ORDER BY count DESC, o

演示