Mega Code Archive
Query Notifications
<![CDATA[
#include "stdafx.h"
using namespace System;
using namespace System::Data;
using namespace System::Threading;
using namespace System::Data::SqlClient;
ref class MyNotification
{
public:
MyNotification(String^ connectionString, String^ sql)
{
ConnectionString = connectionString;
Sql = sql;
SqlDependency::Start(ConnectionString);
SyncHandle = gcnew AutoResetEvent(true);
ChargeNotification();
}
void OnChangedHandler(Object^ caller, SqlNotificationEventArgs^ e)
{
if ( e->Source == SqlNotificationSource::Data &&
e->Type == SqlNotificationType::Change &&
(e->Info == SqlNotificationInfo::Delete ||
e->Info == SqlNotificationInfo::Insert ||
e->Info == SqlNotificationInfo::Update) ){
Console::WriteLine(e->Info.ToString());
ChargeNotification();
}
}
void ChargeNotification()
{
SqlConnection^ connection = gcnew SqlConnection(ConnectionString);
connection->Open();
SqlCommand^ WatchCommand = gcnew SqlCommand(Sql, connection);
SqlDependency^ myDependency = gcnew SqlDependency(WatchCommand);
myDependency->OnChange += gcnew OnChangeEventHandler(this, &MyNotification::OnChangedHandler);
SqlDataReader^ myReader = WatchCommand->ExecuteReader();
myReader->Close();
SyncHandle->Set();
}
void Wait()
{
SyncHandle->Reset();
SyncHandle->WaitOne();
}
String^ ConnectionString;
String^ Sql;
AutoResetEvent^ SyncHandle;
};
void main()
{
SqlConnection^ myConnection = nullptr;
SqlConnectionStringBuilder^ connectionBuilder = gcnew SqlConnectionStringBuilder();
connectionBuilder->DataSource = "localhost\\sqlexpress";
connectionBuilder->InitialCatalog = "myCatalog";
connectionBuilder->IntegratedSecurity = true;
myConnection = gcnew SqlConnection(connectionBuilder->ToString());
myConnection->Open();
MyNotification^ commandNotification = gcnew MyNotification(myConnection->ConnectionString,"SELECT ID, Song FROM dbo.Music");
SqlCommand^ testCommand = gcnew SqlCommand("INSERT INTO Music(Song) VALUES('T')",myConnection);
testCommand->ExecuteNonQuery();
commandNotification->Wait();
testCommand->CommandText ="UPDATE Music SET Song='T' WHERE Song='T'";
testCommand->ExecuteNonQuery();
commandNotification->Wait();
testCommand->CommandText = "DELETE FROM Music WHERE Song='T'";
testCommand->ExecuteNonQuery();
commandNotification->Wait();
myConnection->Close();
}
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