using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.Text.RegularExpressions;

public partial class UserDefinedFunctions
{
    [Microsoft.SqlServer.Server.SqlFunction]
    public static SqlBoolean IsMatch(string Input, string Pattern)
    {
        return new SqlBoolean(Regex.IsMatch(Input, Pattern));
    }

    [Microsoft.SqlServer.Server.SqlFunction]
    public static SqlString RegexReplace(string Input, string Pattern, string Replacement)
    {
        return new SqlString(Regex.Replace(Input, Pattern, Replacement));
    }
}

---开启所有服务器配置选项
EXEC sp_configure N'show advanced options', N'1' 
RECONFIGURE WITH OVERRIDE
--开启clr enabled 选项
EXEC sp_configure N'clr enabled', N'1'
RECONFIGURE WITH OVERRIDE 
--关闭所有服务器配置选项
EXEC sp_configure N'show advanced options', N'0' 
RECONFIGURE WITH OVERRIDE
--如果存在权限问题，执行下面一段脚本
alter database [master] set TRUSTWORTHY on
EXEC sp_changedbowner 'sa'

GO
CREATE FUNCTION [dbo].[IsMatch]
(@Input NVARCHAR (4000), @Pattern NVARCHAR (4000))
RETURNS BIT
AS
 EXTERNAL NAME [Regex].[UserDefinedFunctions].[IsMatch]

GO
CREATE FUNCTION [dbo].[RegexReplace]
(@Input NVARCHAR (4000), @Pattern NVARCHAR (4000), @Replacement NVARCHAR (4000))
RETURNS NVARCHAR (4000)
AS
 EXTERNAL NAME [Regex].[UserDefinedFunctions].[RegexReplace]

select dbo.IsMatch('123abc','\d{2}') --查找连续2位数字
select dbo.IsMatch('123abc','\d{4}') --查找连续4位数字
select dbo.RegexReplace('123abc','\d{3}','ABC') --替换连续3位数字为ABC