作用

从数据库发起对外部服务的请求.

应用场景

心跳监测

定时启动站点

服务实现

代码部分(C#)

using System;

using System.Net;

publicpartialclassStoredProcedures

{

[Microsoft.SqlServer.Server.SqlProcedure]

publicstaticvoid UploadString(String url)

{

var client =newWebClient { Encoding = System.Text.Encoding.UTF8 };

client.UploadString(url,String.Empty);

}

}

注: Microsoft.SqlServer.Server.SqlProcedure属于System.Data程序集.

数据库部分

权限配置

USE [Exercise]

GO

ALTERDATABASE [Exercise]SETTRUSTWORTHYON

GO

EXECsp_configure'clr enabled',1

GO

sp_changedbowner'sa'

GO

reconfigure

GO

外部DLL引用配置

外部服务调用

1.  通过EXTERNAL关键字调用外部DLL的方法

CREATEPROCEDURE [dbo].[Exercise_SP_External_UploadString]

@Url [nvarchar](max)

WITHEXECUTEASCALLER

AS

EXTERNAL NAME [SqlserverClr.Service].[StoredProcedures].[UploadString]

GO

2.  以参数的形式调用外部服务

CREATEPROCEDURE [dbo].[Exercise_SP_CallExternalHttpService]

AS

BEGIN

EXEC dbo.[Exercise_SP_UploadString]@Url='http://www.baidu.com/'

END

GO