create table tmp as
with data as (select 'like' as id ,'a9999' as str from dual union allselect 'like'       ,'a9c'          from dual union allselect 'like'       ,'A7007'        from dual union allselect 'like'       ,'123a34cc'     from dual union allselect 'substr'     ,'123,234,345'  from dual union allselect 'substr'     ,'12,34.56:78'  from dual union allselect 'substr'     ,'123456789'    from dual union allselect 'instr'      ,'192.168.0.1'  from dual union allselect 'replace'    ,'(020)12345678' from dual union allselect 'replace'    ,'001517729C28' from dual
)
select * from data ;select * from tmp ;
ID      STR
------- -------------
like    a9999
like    a9c
like    A7007
like    123a34cc
substr  123,234,345
substr  12,34.56:78
substr  123456789
instr   192.168.0.1
replace (020)12345678
replace 001517729C28

select str from tmp where id='like' and regexp_like(str,'A\d+','i'); -- 'i' 忽略大小写
STR
-------------
a9999
a9c
A7007
123a34cc
select str from tmp where id='like' and regexp_like(str, 'a\d+');
STR
-------------
a9999
a9c
123a34ccselect str from tmp where id='like' and regexp_like(str,'^a\d+');
STR
-------------
a9999
a9c
select str from tmp where id='like' and regexp_like(str,'^a\d+$');
STR
-------------
a9999

col str format a15;
selectstr,regexp_substr(str,'[^,]+')     str,regexp_substr(str,'[^,]+',1,1) str,regexp_substr(str,'[^,]+',1,2) str,  -- occurrence 第几个匹配组regexp_substr(str,'[^,]+',2,1) str   -- position 从第几个字符开始匹配
from tmp
where id='substr';
STR             STR             STR             STR             STR
--------------- --------------- --------------- --------------- ---------------
123,234,345     123             123             234             23
12,34.56:78     12              12              34.56:78        2
123456789       123456789       123456789                       23456789selectstr,regexp_substr(str,'\d')        str,regexp_substr(str,'\d+'  ,1,1) str,regexp_substr(str,'\d{2}',1,2) str,regexp_substr(str,'\d{3}',2,1) str
from tmp
where id='substr';
STR             STR             STR             STR             STR
--------------- --------------- --------------- --------------- ---------------
123,234,345     1               123             23              234
12,34.56:78     1               12              34
123456789       1               123456789       34              234select regexp_substr('123456789','\d',1,level) str  --取出每位数字，有时这也是行转列的方式
from dual
connect by level<=9
STR
---------------
1
2
3
4
5
6
7
8
9

col ind format 9999;
selectstr,regexp_instr(str,'\.'    ) ind ,regexp_instr(str,'\.',1,2) ind ,regexp_instr(str,'\.',5,2) ind
from tmp where id='instr';
STR               IND   IND   IND
--------------- ----- ----- -----
192.168.0.1         4     8    10selectregexp_instr('192.168.0.1','\.',1,level) ind ,  -- 点号. 所在的位置regexp_instr('192.168.0.1','\d',1,level) ind    -- 每个数字的位置
from dual
connect by level <=  9IND   IND
----- -----4     18     210     30     50     60     70     90    110     0

selectstr,regexp_replace(str,'020','GZ') str,regexp_replace(str,'(\d{3})(\d{3})','<\2\1>') str -- 将第一、第二捕获组交换位置，用尖括号标识出来
from tmp
where id='replace';
STR             STR             STR
--------------- --------------- ---------------
(020)12345678   (GZ)12345678    (020)<456123>78
001517729C28    001517729C28    <517001>729C28

col row_line format a30;
with sudoku as (select '020000080568179234090000010030040050040205090070080040050000060289634175010000020' as linefrom dual
),
tmp as (select regexp_substr(line,'\d{9}',1,level) row_line,level colfrom sudokuconnect by level<=9
)
select regexp_replace( row_line ,'(\d)(\d)(\d)(\d)(\d)(\d)(\d)(\d)(\d)','\1 \2 \3 \4 \5 \6 \7 \8 \9') row_line
from tmpROW_LINE
------------------------------
0 2 0 0 0 0 0 8 0
5 6 8 1 7 9 2 3 4
0 9 0 0 0 0 0 1 0
0 3 0 0 4 0 0 5 0
0 4 0 2 0 5 0 9 0
0 7 0 0 8 0 0 4 0
0 5 0 0 0 0 0 6 0
2 8 9 6 3 4 1 7 5
0 1 0 0 0 0 0 2 0