Question

我有像

这样的列

periodbal                  balancetype
-------------              -------------
0;15;11;-13;-16;20           ABS
22;25;-78;0;1                ABS
67;89;-36;83;90;55           ABS
…                            ACS
…

我想要检索

periodbal                  balancetype
---------                  -------------
20                            ABS
25                            ABS
90                            ABS

Answer 1

这里的想法是：

对于balancetype的每个值，从periodbal列中提取所有值，将它们转换为单独的行，然后计算每行的平衡类型值的最大值。

即。

PERIODBAL   BALANCETYPE     ID
0           ABS             1
15          ABS             1
11          ABS             1
-13         ABS             1
-16         ABS             1
20          ABS             1

SPLIT FOR ROW＃2

22        ABS          2
25        ABS          2
-78       ABS          2
0         ABS          2
1         ABS          2
......

最后，FETCH MAX（PERIODBAL）并按列balancetype，ID

对数据进行分组

CREATE TABLE SYS.TEST
(
  PERIODBAL    VARCHAR2(50 BYTE),
  BALANCETYPE  VARCHAR2(5 BYTE)
)

INSERT INTO TEST VALUES ('0;15;11;-13;-16;20', 'ABS');
INSERT INTO TEST VALUES ('22;25;-78;0;1', 'ABS');
INSERT INTO TEST VALUES ('67;89;-36;83;90;55 ', 'ABS');
INSERT INTO TEST VALUES ('0;15;10;-13;-16;23', 'ACS');
INSERT INTO TEST VALUES ('0;14;11;-13;-16;25', 'ACS');

溶液：

SELECT BALANCETYPE,MAX(BAL) AS PERIODBAL
FROM
(
SELECT SUB1.*, TRIM(REGEXP_SUBSTR( PERIODBAL, '[^;]+', 1, LVL)) BAL
FROM             (SELECT TEST.*, ROW_NUMBER() OVER (ORDER BY BALANCETYPE ) UNIQ_ID FROM TEST) SUB1 , 
                (SELECT LEVEL LVL FROM DUAL,(SELECT  MAX(LENGTH(REGEXP_REPLACE(PERIODBAL, '[^;]+')))+1 AS MAX_BAL FROM TEST)  TEMP
                 CONNECT BY LEVEL<= TEMP.MAX_BAL ) SUB2
WHERE LENGTH(REGEXP_REPLACE(PERIODBAL, '[^;]+'))+1>= SUB2.LVL
) GROUP BY BALANCETYPE, UNIQ_ID

输出：

BALANCETYPE PERIODBAL
ACS         23
ABS         20
ABS         25
ABS         90
ACS         25

希望它有所帮助，谢谢。

Answer 2

在 MySQL 中，您可以尝试

SELECT balanceType, MAX(CONVERT(SUBSTRING_INDEX(SUBSTRING_INDEX(t.periodBal, ';', n.n), ';', -1), SIGNED INTEGER)) maxValue
FROM SomeData t CROSS JOIN 
(
   SELECT a.N + b.N * 10 + 1 n
     FROM 
    (SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) a
   ,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) b
    ORDER BY n
) n
WHERE n.n <= 1 + (LENGTH(t.periodBal) - LENGTH(REPLACE(t.periodBal, ';', '')))
GROUP BY periodBal, balanceType
ORDER BY periodBal, maxValue;

查看实际操作：SQL Fiddle（稍微调整数据以检查某些边框情况）。

这借鉴了SQL split comma separated row
但是，我能够找到的这种方法最早的SO参考是Creating a MySQL SET's from a string

从包含在sql中以分号分隔的数组的列中检索任何一个最大值

2 个答案: