如何使用正则表达式提取所需信息？

[t122]

数据库中数据如下：
字段：referer
https://forum.csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a
http://csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a
如何实现如下结果
csdn.net
csdn.net

[arrow_gx]

csdn.net
csdn.net

？？ 这个是确定的 ？ 那根本不需要正则表达式的啊

select 'csdn.net' as referer from table

[elvis_gao]

大家踊跃答问题，我是帮楼主顶贴的

[t122]

不好意思，忘记说了，数据库也可以是这样
https://forum.csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a
http://csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a
http://sports.sina.com.cn/
......
结果如下
csdn.net
csdn.net
sina.com.cn
......

[hery2002]

declare @tb table (id int identity(1,1), url nvarchar(100))
insert into @tb
select 'https://forum.csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a'
union all select 'http://csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a'
union all select 'http://sports.sina.com.cn/'

select --substring(url,7,charindex('/',substring(url,7,len(url))-1) 
substring(url,8,len(url)),
substring(url,8,charindex('/',substring(url,8,len(url)))-1),
parsename( substring(url,8,charindex('/',substring(url,8,len(url)))-1),4),
parsename( substring(url,8,charindex('/',substring(url,8,len(url)))-1),3),
parsename( substring(url,8,charindex('/',substring(url,8,len(url)))-1),2),
parsename( substring(url,8,charindex('/',substring(url,8,len(url)))-1),1)

from @tb
---------------------------------------------------------------------------------------------------- ------------------- --------- ------- ------------ ------
forum.csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a          forum.csdn.net      NULL      forum      csdn      net
csdn.net/PointForum/Forum/PostTopic.aspx?forumID=6e0e6207-de3a-4c0b-8f8a-052fcba6392a                csdn.net            NULL      NULL       csdn      net
sports.sina.com.cn/                                                                                  sports.sina.com.cn  sports    sina       com       cn

(3 row(s) affected)

[t122]

楼上的,数据库里也可以有这样一条记录,如下
https://www.cmbchina.com
要求结果如下
cmbchina.com