在甲骨文

没有正则表达式，你需要回复同样的逻辑为你需要的每个子串，每个timi根据th的位置选择初始位置和leght该子字符串的e“终止符”。

/* input data */ 
    with yourTable(column1) as (
     select '/opt/log/data/abcd.efghi.jklmn.aaa.txt' from dual union all 
     select '/opt/log/data/abbbcd.efccghi.jkdsdflmn.abab.txt' from dual union all 
     select '/opt/log/data/nmvcnmcd.efjhjghi.jkvslmn.abcbc.txt' from dual union all 
     select '/opt/log/data/hjsdhj.hjfdhdf.hdfhjd.aghag.txt' from dual union all 
     select '/opt/log/data/dfhjfdhj.yureyer.qwtyq.hjahjh.txt' from dual 
    ) 
/* query */ 
    select substr(column1, instr(column1, '/', -1) +1, instr(column1, '.') - instr(column1, '/', -1)-1) firstDot, 
      substr(column1, instr(column1, '.') +1, instr(column1, '.', 1, 2) - instr(column1, '.') -1) secondDot, 
      substr(column1, instr(column1, '.', 1, 2) +1, instr(column1, '.', 1, 4) - instr(column1, '.', 1, 2) -1) thirdAndFourthDot 
    from yourTable 

给出：

FIRSTDOT  SECONDDOT  THIRDANDFOURTHD 
--------------- --------------- --------------- 
abcd   efghi   jklmn.aaa 
abbbcd   efccghi   jkdsdflmn.abab 
nmvcnmcd  efjhjghi  jkvslmn.abcbc 
hjsdhj   hjfdhdf   hdfhjd.aghag 
dfhjfdhj  yureyer   qwtyq.hjahjh 

在一个更可读的方式：

select substr(column1, lastSlashPos +1, firstDotPos - lastSlashPos -1) as firstDot, 
     substr(column1, firstDotPos +1, secondDotPos - firstDotPos -1) as secondDot, 
     substr(column1, secondDotPos +1, fourthDotPos - secondDotPos -1) as thirdAndFourthDot 
from (
     select instr(column1, '/', -1) as lastSlashPos, 
       instr(column1, '.') as firstDotPos, 
       instr(column1, '.', 1, 2) as secondDotPos, 
       instr(column1, '.', 1, 3) as thirdDotPos, 
       instr(column1, '.', 1, 4) as fourthDotPos, 
       column1 
     from yourTable 
    ) 

select substr('/opt/log/data/abcd.efghi.jklmn.aaa.txt',instr('/opt/log/data/abcd.efghi.jklmn.aaa.txt','/',-1) + 1) from dual; 

这会给你以后最后/

文本，然后你需要申请instr为.：

select 
    substr(text, 1, instr(text,'.', 1) - 1), 
    substr(text, instr(text,'.', 1) + 1, instr(text,'.', 2) - 1), 
    substr(text, instr(text,'.', 2) + 1) 
from (
    select substr('/opt/log/data/abcd.efghi.jklmn.aaa.txt',instr('/opt/log/data/abcd.efghi.jklmn.aaa.txt','/',-1) + 1) text from dual 
);