不定期更新
把AAAA替换为A-A-A-A-
javascript
alert('AAAA'.replace(/([A]{1})/g,"$1-"));
()中的内容用变量 2 $n代替
PostgreSQL
select regexp_replace('AAAAAAAAAAAAAAAAAAAAAA','([A-Z]{1})','\1-','g')
()中的内容用变量\1 \2 \n代替
获取大括号中的内容
select f1[1] from regexp_matches('asdfadfadsf{_id}','[\{]{1}(.*?)[\}]{1}') as f1
字符串去重
-- \1表示只匹配第一个子串
select regexp_replace('adsfjjbkk中中','(.)(\1)+','\1','g')
select regexp_replace('adaaasfjjjbkk','(.).*(\1)+','\1','g')
去除字符串最后两位
select substring('abc123d4' from '^(.*?)..$');
-output abc123
擦除所有空格
select * from regexp_matches(' abc123d 4测试 ','[^ ]+','g');
select * from regexp_matches(' abc123d4测试 ','[^ ]+','g');
-output abc123
擦除左右两边的空格
select regexp_replace(' abc123d4 测试 ','^[ ]?(.*?)[ ]?$','\1','g');
从html中提取字符串
select f1 from regexp_split_to_table('<div id="u1"><a href="http://news.baidu.com" name="tj_trnews" class="mnav">新闻</a><a href="https://www.hao123.com" name="tj_trhao123" class="mnav">hao123</a><a href="http://map.baidu.com" name="tj_trmap" class="mnav">地图</a><a href="http://v.baidu.com" name="tj_trvideo" class="mnav">视频</a><a href="http://tieba.baidu.com" name="tj_trtieba" class="mnav">贴吧</a><a href="http://xueshu.baidu.com" name="tj_trxueshu" class="mnav">学术</a><a href="https://passport.baidu.com/v2/?login&tpl=mn&u=http%3A%2F%2Fwww.baidu.com%2F&sms=5" name="tj_login" class="lb" onclick="return false;">登录</a><a href="http://www.baidu.com/gaoji/preferences.html" name="tj_settingicon" class="pf">设置</a><a href="http://www.baidu.com/more/" name="tj_briicon" class="bri" style="display: block;">更多产品</a></div>','<[^>]*>') as f1 where f1<>''
取开头4个字符和最后4个字符
with cte as(
select '实际月份少一个月a1.' as f limit 1
) select (regexp_matches(f,'^(.{4})'))[1] as start,(regexp_matches(f,'(.{4})$'))[1] as end from cte