我想第一次尝试SqlDepenedency。我没有收到有关数据库更新的任何通知。SqlDependency没有触发
我把里面的断点: OnChange(object sender, SqlNotificationEventArgs e)
,
但它从来没有被击中。
这里是我的代码:
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = "Cache Refresh: " + DateTime.Now.ToLongTimeString();
DateTime.Now.ToLongTimeString();
// Create a dependency connection to the database.
SqlDependency.Start(GetConnectionString());
using (SqlConnection connection = new SqlConnection(GetConnectionString()))
{
using (SqlCommand command = new SqlCommand(GetSQL(), connection))
{
SqlDependency dependency =
new SqlDependency(command);
// Refresh the cache after the number of minutes
// listed below if a change does not occur.
// This value could be stored in a configuration file.
connection.Open();
dgHomeRequests.DataSource = command.ExecuteReader();
dgHomeRequests.DataBind();
}
}
}
private string GetConnectionString()
{
// To avoid storing the connection string in your code,
// you can retrieve it from a configuration file.
//return "Data Source=(local);Integrated Security=true;" +"Initial Catalog=AdventureWorks;";
return ConfigurationManager.ConnectionStrings["TestData"].ConnectionString;
}
private string GetSQL()
{
return "Select [Address] From [UserAccount1]";
}
void OnChange(object sender, SqlNotificationEventArgs e)
{
// have breakpoint here:
SqlDependency dependency = sender as SqlDependency;
// Notices are only a one shot deal
// so remove the existing one so a new
// one can be added
dependency.OnChange -= OnChange;
// Fire the event
/* if (OnNewMessage != null)
{
OnNewMessage();
}*/
}
我也已经把一些代码在Global.asax文件:
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
SqlDependency.Start(ConfigurationManager.ConnectionStrings["TestData"].ConnectionString);
}
protected void Application_End()
{
// Shut down SignalR Dependencies
SqlDependency.Stop(ConfigurationManager.ConnectionStrings["TestData"].ConnectionString);
}
}
SQL服务器是本地机器上。我通过Visual Studio(IIS Express)运行代码。
要在数据库中启用服务代理:
ALTER DATABASE SET ENABLE_BROKER GO
要订阅查询通知,我们需要给权限的IIS服务帐户
GRANT SUBSCRIBE QUERY NOTIFICATIONS TO “<serviceAccount>”
我猜想第二点是不需要的,因为我t是本地的。但我试着给它一些权限。不知道他们是否正确,因为我不认为它使用应用程序池。并且不需要本地环境许可。如果我是我自己的用户并自己创建架构。
其中之一,我看到被授予问题:
alter authorization on database::<dbName> to [sa];
我给这个权限了。
你可以检查两件事情:1),该通知是“设置” ,请参阅['sys.dm_qn_subscriptions'](https://docs.microsoft.com/zh-cn/sql/relational-databases/system-dynamic-management-views/query-notifications-sys-dm-qn-subscriptions)和2)通知消息不保留在['sys.transmission_queue'](https://docs.microsoft.com/en-us/sql/relational -databases/system-catalog-views/sys-transmission-queue-transact-sql) –
@RemusRusanu我进入了视图,为sys.dm_qn_subscriptions和sys.transmission_queue选择了前1000行。他们都在那里,他们都是空的。任何异常? –
'sys.qn_subscriptions'中应该有一行。我怀疑你的查询通知立即失效,因为它违反了[这里]列出的某个限制(https://technet.microsoft.com/en-us/library/ms181122(v = sql.105).aspx)。你可以使用一个基本的'SqlDependency'而不是'SqlCacheDependency'并且忽略你在['SqlNotificationEventArgs'](https://msdn.microsoft.com/en- us/library/system.data.sqlclient.sqlnotificationeventargs(v = vs.110).aspx) –