之前曾有一篇
POST是关于用CTE实现Split，这种方法已经比传统的方法高效了。今天我们就这个方法与CLR实现的Split做比较。在CLR实现Split函数的确很简单，dotnet framework本身就有这个function了。
我们新建一个c#-数据库工程，然后建立一个用户自定义函数,Code像这样:
我们新建一个c#-数据库工程，然后建立一个用户自定义函数,Code像这样:
1: /// <summary>
2: /// SQLs the array.
3: /// </summary>
4: /// <param name="str">The STR.</param>
5: /// <param name="delimiter">The delimiter.</param>
6: /// <returns></returns>
7: /// 1/8/2010 2:41 PM author: v-pliu
8: [SqlFunction(Name = "CLR_Split",
9: FillRowMethodName = "FillRow",
10: TableDefinition = "id nvarchar(10)")]
11:
12: public static IEnumerable SqlArray(SqlString str, SqlChars delimiter)
13: {
14: if (delimiter.Length == 0)
15: return new string[1] { str.Value };
16: return str.Value.Split(delimiter[0]);
17: }
18:
19: /// <summary>
20: /// Fills the row.
21: /// </summary>
22: /// <param name="row">The row.</param>
23: /// <param name="str">The STR.</param>
24: /// 1/8/2010 2:41 PM author: v-pliu
25: public static void FillRow(object row, out SqlString str)
26: {
27: str = new SqlString((string)row);
28: }
然后编译,部署一切OK后，在SSMS中执行以下测试T-sql:
1: DECLARE @array VARCHAR(max)
2: SET @array = '39,15,93,68,64,43,90,58,39,9,26,26,89,47,91,57,98,16,55,9,63,29,69,16,41,76,34,60,68,64,61,53,32,30,11,72,57,63,36,43,22,14,60,38,24,5,66,26,26,21,22,99,55,18,7,10,46,76,27,88,9,29,89,75,48,72,94,59,35,19,0,35,79,11,87,49,68,30,91,35,9,7,34,47,41,61,98,13,22,1,26,80,35,48,34,92,24,85,90,51'
3: SELECT id FROM dbo.CLR_Split(@array,',')
我们来看它的Client Statistic:
接着我们执行测试T-sql使用相同的array:
1: DECLARE @array VARCHAR(max)
2: SET @array = '39,15,93,68,64,43,90,58,39,9,26,26,89,47,91,57,98,16,55,9,63,29,69,16,41,76,34,60,68,64,61,53,32,30,11,72,57,63,36,43,22,14,60,38,24,5,66,26,26,21,22,99,55,18,7,10,46,76,27,88,9,29,89,75,48,72,94,59,35,19,0,35,79,11,87,49,68,30,91,35,9,7,34,47,41,61,98,13,22,1,26,80,35,48,34,92,24,85,90,51'
3: SELECT item FROM strToTable(@array,',')
CTE实现的Split function的Client statistic:
通过对比，你可以发现CLR的performance略高于CTE方式，原因在于CLR方式有Cache功能，并且把一个复杂的运算放到程序里比DataBase里更加高效。
您还可以参考：
Split string in SQL Server 2005+ CLR vs. T-SQL
Author:Petter Liu http://wintersun.cnblogs.com/
希望这篇POST对您有帮助。
出现禁止在 .NET Framework 中执行用户代码。启用 "clr enabled" 配置选项错误。
解决方法：查询分析器中运行如下代码即可：
exec sp_configure 'show advanced options', '1';
go
reconfigure;
go
exec sp_configure 'clr enabled', '1'
go
reconfigure;
exec sp_configure 'show advanced options', '1';
go
本文转自温景良(Jason)博客园博客，原文链接：http://www.cnblogs.com/wenjl520/archive/2010/01/09/1642736.html如需转载请自行联系原作者
