本来一直反对在sql server中使用clr的，但是无奈在我之前，网站已经被人开启clr，所以今天干脆偶也来实现一个clr的trigger，用于在文章表内建立一个insert 触发器，每次发表文章，均ping一次google的博客接口。
过程如下：
1 建立sql server 项目，选择触发器
2 写代码：
Code
public partial class Triggers
{
// 为目标输入现有表或视图并取消对属性行的注释
[Microsoft.SqlServer.Server.SqlTrigger (Name="Articletrigger", Target="cyzonearticle", Event="FOR INSERT")]
public static void Articletrigger()
{
try
{
SqlTriggerContext triggContext = SqlContext.TriggerContext;
// SqlParameter userName = new SqlParameter("@username", System.Data.SqlDbType.NVarChar);
if (triggContext.TriggerAction == TriggerAction.Insert)
{
using (SqlConnection conn = new SqlConnection("context connection=true"))
{
conn.Open();
SqlCommand sqlComm = new SqlCommand();
SqlPipe sqlP = SqlContext.Pipe;
sqlComm.Connection = conn;
sqlComm.CommandText = @"select i.articleid,i.userid,i.time,i.publishtype,u.username,u.blogname,u.createtime,dbo.GetLinkUrl(i.articleid,i.publishtype,u.username,i.time) as url from inserted i
inner join userbase u on(i.userid = u.userid)";
DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(sqlComm);
da.Fill(ds);
DataRow dr = ds.Tables[0].Rows[0];
string articleid = dr["articleid"].ToString();
string userid = dr["userid"].ToString();
DateTime time = Convert.ToDateTime(dr["time"]);
string publishtype = dr["publishtype"].ToString();
string username = dr["username"].ToString();
DateTime createtime = Convert.ToDateTime(dr["createtime"]);
string blogname = dr["blogname"].ToString();
string url = dr["url"].ToString();
string rssurl = "";
if (publishtype.ToLower()=="a" || publishtype.ToLower()=="b" || publishtype.ToLower()=="c" )
{
rssurl = "http://www.cyzone.cn/blog/" + username + "/rss.aspx";
}
if ((time - createtime) > new TimeSpan(3, 0, 0, 0))
{
string returns = PingGoogleBlogService(blogname, url, rssurl);
string flag = "0";
if (returns != "Thanks for the ping.")
{
flag = "1";
}
sqlComm.CommandText = "INSERT X_Google_Blog_Ping_Log(articleid,time,flag) VALUES('" + articleid + "','" + time + "','" + flag + "')";
sqlP.Send(sqlComm.CommandText);
sqlP.ExecuteAndSend(sqlComm);
}
}
}
}
catch (Exception ee)
{
System.IO.StreamWriter sw = new System.IO.StreamWriter(@"E:\services\GooglePingDll\xx.txt");
sw.WriteLine(ee.Message+ee.Source);
sw.Close();
}
}
private static string PingGoogleBlogService(string blogname, string url, string rssurl)
{
WebClient w = new WebClient();
Uri uri ;
if (string.IsNullOrEmpty(rssurl))
uri = new Uri("http://blogsearch.google.com/ping?name=" + blogname + "&url=" + url, false);
else
uri = new Uri("http://blogsearch.google.com/ping?name=" + blogname + "&url=" + url+"&changesURL="+rssurl,false);
return w.DownloadString(uri);
}
}
3 编译项目，上传dll到服务器指定目录
4 开启clr（偶的服务器已经默认开启）
5 USE cyzone
GO
EXEC sp_changedbowner 'sa' （更改安全主体，有些服务器不需要）
6 ALTER DATABASE cyzone SET TRUSTWORTHY ON
7 CREATE ASSEMBLY GooleBlogPingService
FROM 'E:"services"GooglePingDll"GoogleBlogPingServiceSqlFunction.dll'
WITH PERMISSION_SET = unSAFE;
8 Create Trigger tr_aasdasd
on cyzonearticle
For INSERT
AS
External Name GooleBlogPingService.Triggers.Articletrigger
Go
其中有几点要注意的是：
如果您的触发器程序中没有访问到数据库服务器的外部资源，可以将权限设置为安全模式，并且略去第5步和第6步
最后一步也是将触发器和程序集挂钩。
这个名称 GooleBlogPingService.Triggers.Articletrigger 是比较讲究的，他的组成是：程序集名称.类名.方法名
that's all.
