1、开发过程经常遇到“列转行\行转列”问题,如下图
2、列转行
2.1 现场数据库一般会有中文逗号,分号、、、、、等情况。转之前我们先进行替换
select
(SELECT REGEXP_REPLACE(m.ALTBE,'[;||;||,||、]', ',') AS NAMES FROM DUAL)
from REG_AltAccItem m WHERE id = '141000013302990181'
2.2 列转行
SELECT REGEXP_SUBSTR('100000003,100000007,100000018,100000020,100000021,100000022,100000023,410000002,410000003,','[^,]+', 1, ROWNUM) AS code FROM DUAL
CONNECT BY ROWNUM <= LENGTH(REGEXP_REPLACE('100000003,100000007,100000018,100000020,100000021,100000022,100000023,410000002,410000003,', '[^,]+', NULL)) + 1
3、行转列
参数解释
String:需要进行正则处理的字符串。
pattern:正则表达式。
position:起始位置(从字符串的第几个开始正则,默认为1,注:数据库中的字符串起始位置为1)。
occurrence:获取第几组通过正则表达式分割出来的组。
modifier:模式(‘i’不区分大小写,‘c’区分大小写。其中默认没‘c’)。
SELECT wm_concat(NAME) FROM (
select NAME from CODE_REGALLLICCODE a INNER JOIN (
SELECT REGEXP_SUBSTR('100000003,100000007,100000018,100000020,100000021,100000022,100000023,410000002,410000003,','[^,]+', 1, ROWNUM) AS code FROM DUAL
CONNECT BY ROWNUM <= LENGTH(REGEXP_REPLACE('100000003,100000007,100000018,100000020,100000021,100000022,100000023,410000002,410000003,', '[^,]+', NULL)) + 1) b ON a.CODE = b.code
)