Oracle中出现单个逗号时拆分字符串，出现多个逗号时不拆分

Question

--案例#1

select '1,2,,2,3,4,,,4,5, , ,, , ,, , ,,,,,,5,6' from dual;

--案例#2

select q'[1aaaaaa, bbb,  bbbb (cccc,,ccccc) 20,,,20-09-30 11:11:11 (dddddddd): below eeeeeee is ddddd of teh dddd. ajhvajshbfjasbhfjkabsdfkjabsfkljbaaksjfka . 569716476@@asdasa asdasdi (asfasfasf) 2020-09-30 22:22:27 (sdfsdfal): As per sdfsdfsdfg sdfm: sds the below is a sdfsdf@@@@3**** sd sd sdd sdffve sdffin with sdf ��� the below is correct. the "sdfd" sds tsd sdfe fsI as sdfL. hsdfe we do not sdffte fsw dsddDs123**** just new sdfsdng ssdfsds.@@sdfsda sdfsdni (sdffdsdUP) 2020-09-23 22:31:54 (sdffsdal): sdil zxct cx Gzxcz zxcc: zxcc/zxI-Jcxz- cx zxccx***zxccc rzxcczxc***. 569zxc476@@zxccxi zxcxzze (zxcczxzxc) 2020-02-28 22:21:26, (zxtezxcxz) 03/28-As per zxcc, ,, ,,, , ,,,,,, ,zxzxx by cx cxcx zxzz is zxcxzz zxcxz zxcc. zxc zx]'
from dual;

--案例#3

Please just copy paste the string present in Case#2 several times so that the overall length increase 4000 characters and try you solution.

这个字符串应该在单个逗号出现时拆分，并且不应拆分多次出现的逗号，如 double/triple 等。

此外，如果任何人都可以用 12345 之类的字符串替换上面的多个逗号，那么它将对我有用。不要替换单个逗号

请注意，上面的字符串来自 CLOB 列，因此需要一个高效的查询，它应该花费更少 cpu。

o/p:
1
2,,2
3
4,,,4
5, , ,, , ,, , ,,,,,,5     -- NOTE: this has multiple commas with space
6

Answer 1

从 Oracle 11gR2 开始，您可以使用：

WITH strings (value, end_pos, term) AS (
  SELECT value,
         REGEXP_INSTR(value, '((\d+(, *){2,})*\d+)(,|$)', 1, 1, 1),
         REGEXP_SUBSTR(value, '((\d+(, *){2,})*\d+)(,|$)', 1, 1, NULL, 1)
  FROM   table_name
UNION ALL
  SELECT value,
         REGEXP_INSTR(value, '((\d+(, *){2,})*\d+)(,|$)', end_pos, 1, 1),
         REGEXP_SUBSTR(value, '((\d+(, *){2,})*\d+)(,|$)', end_pos, 1, NULL, 1)
  FROM   strings
  WHERE  end_pos > 0
)
SELECT term
FROM   strings
WHERE  end_pos > 0;

其中，对于示例数据：

CREATE TABLE table_name ( value ) AS
select '1,2,,2,3,4,,,4,5, , ,, , ,, , ,,,,,,5,6' from dual;

输出：

TERM

1

2,,2

3

4,,,4

5, , ,, , ,, , ,,,,,,5

6

可能适用于早期版本的替代方法是：

SELECT RTRIM(
         REGEXP_SUBSTR(
           t.value,
           '((\d+(, *){2,})*\d+)(,|$)',
           1,
           l.COLUMN_VALUE
         ),
         ','
       ) AS term
FROM   table_name t
       CROSS JOIN
       TABLE(
         CAST(
           MULTISET(
             SELECT LEVEL
             FROM   DUAL
             CONNECT BY
                    REGEXP_INSTR(
                      t.value,
                      '((\d+(, *){2,})*\d+)(,|$)',
                      1,
                      LEVEL
                    ) > 0
           )
           AS SYS.ODCINUMBERLIST
         )
       ) l

sqlfiddle here

Oracle中出现单个逗号时拆分字符串，出现多个逗号时不拆分

Split string when single comma occurs and not split when more than one comma occurs in Oracle

oracle

oracle11g

oracle10g