引用

https://www.cnblogs.com/keepfool/archive/2012/03/25/2416911.html

CREATE function dbo.regexReplace 
( 
@source ntext, --原字符串
@regexp varchar(1000), --正则表达式
@replace varchar(1000), --替换值
@globalReplace bit = 1, --是否是全局替换
@ignoreCase bit = 0 --是否忽略大小写
) 
returnS varchar(1000) AS 
begin 
declare @hr integer 
declare @objRegExp integer 
declare @result varchar(5000) 

exec @hr = sp_OACreate 'VBScript.RegExp', @objRegExp OUTPUT 
IF @hr <> 0 begin 
exec @hr = sp_OADestroy @objRegExp 
return null 
end 
exec @hr = sp_OASetProperty @objRegExp, 'Pattern', @regexp 
IF @hr <> 0 begin 
exec @hr = sp_OADestroy @objRegExp 
return null 
end 
exec @hr = sp_OASetProperty @objRegExp, 'Global', @globalReplace 
IF @hr <> 0 begin 
exec @hr = sp_OADestroy @objRegExp 
return null 
end 
exec @hr = sp_OASetProperty @objRegExp, 'IgnoreCase', @ignoreCase 
IF @hr <> 0 begin 
exec @hr = sp_OADestroy @objRegExp 
return null 
end 
exec @hr = sp_OAMethod @objRegExp, 'Replace', @result OUTPUT, @source, @replace 
IF @hr <> 0 begin 
exec @hr = sp_OADestroy @objRegExp 
return null 
end 
exec @hr = sp_OADestroy @objRegExp 
IF @hr <> 0 begin 
return null 
end 

return @result 
end 

需要注意的是，即使写好了这个函数，也并不能马上使用。执行这个函数时可能会出现以下的错误：

Msg 15281, Level 16, State 1, Line 1 SQL Server blocked access to procedure 'sys.sp_OACreate' of component 'Ole Automation Procedures' because this component is turned off as part of the security configuration for this server. A system administrator can enable the use of 'Ole Automation Procedures' by using sp_configure. For more information about enabling 'Ole Automation Procedures', see "Surface Area Configuration" in SQL Server Books Online.

这是因为未开启Ole Automation Procedures选项，MSDN中的Ole Automation Procedures选项。执行下面的语句开启这个选项：

sp_configure 'show advanced options', 1;
GO
RECONFIGURE;
GO
sp_configure 'Ole Automation Procedures', 1;
GO
RECONFIGURE;
GO

Example1：忽略大小写并替换

select dbo.regexReplace('<A HREF="www.jileiba.com" target="_blank" style="color:red;">123456</a>','<a[^>]*>[^<]*</a>','',1,1)

Example2: 使用贪婪匹配

declare @html nvarchar(4000)='<p>
    Also Available - <a style="text-decoration: none" href="/isbn/9780199218691"><font
        color="#000FF"><b>Smith & Hogan: Criminal Law Cases & Materials 10th ed</b></font></a>
    <p>
        There is, as ever, detailed analysis of the many recent case developments, in particular,
        a revision of the chapter dealing with secondary liability and joint enterprise.</p>
</p>'

select dbo.regexReplace(@html,'<a[^>]*>(.|\n)*?</a>','',1,1)

Example3：去除html标签

select dbo.regexReplace('<p><b>Key Contact:</b><br> Mr  Jack,  Zhou<br> General Manager<br> <p> Mr  Adu,  Ho<br> Marketing Director<br> Overseas Sales<br> <p> Ms  Winny,  Luo<br> Sales Manager<br> Overseas Sales<br> <p>'
,'<[^>]*>','',1,0) 

Example4：数据库字段值替换

update Books 
set [Description] = dbo.regexReplace([Description],'<a[^>]*>(.|\n)*?</a>','',1,1)