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。
------解决方案--------------------
- SQL code
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