我刚刚实现了一个原型解决方案,通过将 CLR 触发器分配给表来实时更新我的缓存服务器,这样每当更新某个列时,从触发器调用的 URL 都会使用正确的数据更新缓存服务器。
它工作正常,代码如下:
[Microsoft.SqlServer.Server.SqlTrigger(Name = "AdStatusChanged", Target = "Ads", Event = "FOR UPDATE")]
public static void AdStatusChanged()
{
SqlTriggerContext triggContext = SqlContext.TriggerContext;
int adID = 0, adStatusID_Old = 0, adStatusID_New = 0;
if (triggContext.TriggerAction == TriggerAction.Update)
{
using (SqlConnection conn = new SqlConnection("context connection=true"))
{
conn.Open();
SqlCommand sqlComm = new SqlCommand();
SqlPipe sqlP = SqlContext.Pipe;
sqlComm.Connection = conn;
sqlComm.CommandText = "SELECT AdID, AdStatusID from INSERTED";
SqlDataReader reader = sqlComm.ExecuteReader();
if (reader.Read())
{
adID = reader.GetInt32(0);
adStatusID_New = reader.GetInt32(1);
}
reader.Close();
sqlComm.CommandText = "SELECT AdID, AdStatusID from DELETED WHERE AdID = " + adID;
reader = sqlComm.ExecuteReader();
if (reader.Read())
{
adID = reader.GetInt32(0);
adStatusID_Old = reader.GetInt32(1);
}
}
if (adID == 0 || adStatusID_New == adStatusID_Old)
{
// Check could be more thorough !
return;
}
WebResponse httpResponse = null;
try
{
string apiURL = string.Format("{0}/{1}", "http://localhost:14003/Home", "UpdateAdStatus?adID=" + adID + "&adStatusID=" + adStatusID_New);
var httpWebRequest = (HttpWebRequest)WebRequest.Create(apiURL);
httpWebRequest.Method = "GET";
httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
// check for successful response
}
catch (Exception ex)
{
Log("WebRequest from within SQL Server failed ! " + ex.Message);
}
finally
{
if (httpResponse != null)
{
httpResponse.Close();
}
}
}
}
关于性能、死锁、sql 崩溃或其他可能引起关注的领域,我想对这种方法的“缺点”有一些专家/经验丰富的看法。
有没有人尝试过这个(我相信很多人必须有),结果如何?一个成功的实现,还是您恢复到其他方法或实时更新缓存?