select regexp_instr('but, soft! what light through yonder windows breaks?','l[[:alpha:]]{4}')
as result from dual中{4}是什么意思?
与select regexp_instr('but, soft! what light through yonder windows breaks?','l[[:alpha:]]')
as result from dual返回结果一致。
as result from dual中{4}是什么意思?
与select regexp_instr('but, soft! what light through yonder windows breaks?','l[[:alpha:]]')
as result from dual返回结果一致。
select regexp_instr('but, soft! what light through yonder windows breaks?',
'l[[:alpha:]]{4}') as result --匹配l[[:alpha:]]{4}表示l后面有4个字母
from dual
select regexp_instr('but, soft! what light through yonder windows breaks?',
'l[[:alpha:]]') as result --匹配l[[:alpha:]]后面一个字母
from dual