Hello.
I have implemented and tested a SqlDependency in a Windows Application example on MSDN: https://msdn.microsoft.com/en-us/library/a52dhwx7(v=vs.80).aspx
Unfortunately the example is not running.
I tried to set up all the necessary options on SQL Server as well which I found on:
I enclose source code for both Watcher and Updater application and also SQL Script which should enable all the necessary settings on SQL Server to allow SQL Notifications using SqlDependency.
I will be glad for any help. Is there something I missed?
Thank you very much in advance.
Best Regards,
Zdeněk Neustupa
----------------------------------- Watcher Application --------------------------------------------
public partial class MainWindow : Window
{
private int changeCount = 0;
private const string tableName = "Technician";
private const string statusMessage = "{0} changes have occurred.";
private DataSet dataToWatch = null;
private SqlConnection connection = null;
private SqlCommand command = null;
public MainWindow()
{
InitializeComponent();
bGetData.IsEnabled = CanRequestNotifications();
}
private bool CanRequestNotifications()
{
try
{
SqlClientPermission perm = new SqlClientPermission(PermissionState.Unrestricted);
perm.Demand();
return true;
}
catch
{
return false;
}
}
private string GetConnectionString()
{
return @"Server=server08\SQLSERVER2008;Database=emistar;User Id=terminal01;Password=TinT434041,;";
}
private string GetSQL()
{
return "SELECT TechnicianName FROM Technician ORDER BY TechnicianName ASC";
}
private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
{
ISynchronizeInvoke i = (ISynchronizeInvoke)this;
if (i.InvokeRequired)
{
OnChangeEventHandler tempDelegate =
new OnChangeEventHandler(dependency_OnChange);
object[] args = { sender, e };
i.BeginInvoke(tempDelegate, args);
return;
}
SqlDependency dependency = (SqlDependency)sender;
dependency.OnChange -= dependency_OnChange;
++changeCount;
lChanges.Content = String.Format(statusMessage, changeCount);
lbSelect.Items.Clear();
lbSelect.Items.Add("Info: " + e.Info.ToString());
lbSelect.Items.Add("Source: " + e.Source.ToString());
lbSelect.Items.Add("Type: " + e.Type.ToString());
GetData();
}
private void GetData()
{
dataToWatch.Clear();
command.Notification = null;
SqlDependency dependency = new SqlDependency(command, "Service='ChangeNotifications'", 0);
dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataToWatch, tableName);
dgMain.ItemsSource = dataToWatch.Tables["Technician"].DefaultView;
}
}
private void bGetData_Click(object sender, EventArgs e)
{
changeCount = 0;
lChanges.Content = String.Format(statusMessage, changeCount);
SqlDependency.Stop(GetConnectionString(), "ChangeMessages");
SqlDependency.Start(GetConnectionString(), "ChangeMessages");
if (connection == null)
{
connection = new SqlConnection(GetConnectionString());
}
if (command == null)
{
command = new SqlCommand("SelectTechnicians", connection);
command.CommandType = CommandType.StoredProcedure;
}
if (dataToWatch == null)
{
dataToWatch = new DataSet();
}
GetData();
}
}--------------------------------------------- Updater Application --------------------------------------------------
public partial class MainWindow : Window
{
private SqlConnection connection = null;
private SqlCommand command = null;
public MainWindow()
{
InitializeComponent();
}
private string GetConnectionString()
{
return @"Server=server08\SQLSERVER2008;Database=emistar;User Id=terminal01;Password=TinT434041,;";
}
private string GetSQL()
{
return "UPDATE emistar.dbo.Technician SET TechnicianName=@TechName WHERE TechnicianID=1";
}
private void bInsertClick(object sender, EventArgs e)
{
string techName = txtName.Text;
if (connection == null)
{
connection = new SqlConnection(GetConnectionString());
connection.Open();
}
if (command == null)
{
command = new SqlCommand(GetSQL(), connection);
SqlParameter param = new SqlParameter("@TechName", SqlDbType.NVarChar);
param.Direction = ParameterDirection.Input;
param.DbType = DbType.String;
command.Parameters.Add(param);
}
command.Parameters["@TechName"].Value = techName;
int rowsAffected = command.ExecuteNonQuery();
txtName.Clear();
MessageBox.Show(rowsAffected + " records updated.", "Update");
}
private void windowClosing(object sender, EventArgs e)
{
if (connection != null)
{
connection.Close();
}
}
}--------------------------------------------- SQL Server Settings ---------------------------------------------
ALTER DATABASE emistar SET ENABLE_BROKER; CREATE QUEUE ChangeMessages; CREATE SERVICE ChangeNotifications ON QUEUE ChangeMessages([http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification]); --DBA creates a new role EXEC sp_addrole 'sql_dependency_subscriber' --------------------- User terminal01 ----------------------------- GRANT SUBSCRIBE QUERY NOTIFICATIONS TO terminal01 --Permission needed for startUser GRANT CREATE PROCEDURE to terminal01 GRANT CREATE QUEUE to terminal01 GRANT CREATE SERVICE to terminal01 GRANT REFERENCES on CONTRACT::[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to terminal01 GRANT VIEW DEFINITION TO terminal01 --Permissions needed for executeUser GRANT SELECT to terminal01 GRANT SUBSCRIBE QUERY NOTIFICATIONS TO terminal01 GRANT RECEIVE ON QueryNotificationErrorsQueue TO terminal01 GRANT REFERENCES on CONTRACT::[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to terminal01 EXEC sp_addrolemember 'sql_dependency_subscriber', 'terminal01' GRANT RECEIVE ON ChangeMessages TO terminal01; GRANT SEND ON SERVICE::ChangeNotifications TO terminal01; GRANT CREATE PROCEDURE to terminal01; GRANT CREATE QUEUE to terminal01; GRANT CREATE SERVICE to terminal01; GRANT SUBSCRIBE QUERY NOTIFICATIONS TO terminal01; GRANT INSERT ON SCHEMA::dbo TO terminal01; GRANT SELECT ON SCHEMA::dbo TO terminal01; GRANT ALTER ON SCHEMA::dbo TO terminal01; GRANT CONTROL ON SCHEMA::dbo TO terminal01; --GRANT CREATE SEQUENCE ON SCHEMA::dbo TO terminal01; GRANT DELETE ON SCHEMA::dbo TO terminal01; GRANT EXECUTE ON SCHEMA::dbo TO terminal01; GRANT INSERT ON SCHEMA::dbo TO terminal01; GRANT REFERENCES ON SCHEMA::dbo TO terminal01; GRANT SELECT ON SCHEMA::dbo TO terminal01; GRANT TAKE OWNERSHIP ON SCHEMA::dbo TO terminal01; GRANT UPDATE ON SCHEMA::dbo TO terminal01; GRANT VIEW CHANGE TRACKING ON SCHEMA::dbo TO terminal01; GRANT VIEW DEFINITION ON SCHEMA::dbo TO terminal01; --------------------- User terminal02 ----------------------------- GRANT SUBSCRIBE QUERY NOTIFICATIONS TO terminal02 --Permission needed for startUser GRANT CREATE PROCEDURE to terminal02 GRANT CREATE QUEUE to terminal02 GRANT CREATE SERVICE to terminal02 GRANT REFERENCES on CONTRACT::[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to terminal02 GRANT VIEW DEFINITION TO terminal02 --Permissions needed for executeUser GRANT SELECT to terminal02 GRANT SUBSCRIBE QUERY NOTIFICATIONS TO terminal02 GRANT RECEIVE ON QueryNotificationErrorsQueue TO terminal02 GRANT REFERENCES on CONTRACT::[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to terminal02 EXEC sp_addrolemember 'sql_dependency_subscriber', 'terminal02' GRANT RECEIVE ON ChangeMessages TO terminal02; GRANT SEND ON SERVICE::ChangeNotifications TO terminal02; GRANT CREATE PROCEDURE to terminal02; GRANT CREATE QUEUE to terminal02; GRANT CREATE SERVICE to terminal02; GRANT SUBSCRIBE QUERY NOTIFICATIONS TO terminal02; GRANT INSERT ON SCHEMA::dbo TO terminal02; GRANT SELECT ON SCHEMA::dbo TO terminal02; GRANT ALTER ON SCHEMA::dbo TO terminal02; GRANT CONTROL ON SCHEMA::dbo TO terminal02; --GRANT CREATE SEQUENCE ON SCHEMA::dbo TO terminal02; GRANT DELETE ON SCHEMA::dbo TO terminal02; GRANT EXECUTE ON SCHEMA::dbo TO terminal02; GRANT INSERT ON SCHEMA::dbo TO terminal02; GRANT REFERENCES ON SCHEMA::dbo TO terminal02; GRANT SELECT ON SCHEMA::dbo TO terminal02; GRANT TAKE OWNERSHIP ON SCHEMA::dbo TO terminal02; GRANT UPDATE ON SCHEMA::dbo TO terminal02; GRANT VIEW CHANGE TRACKING ON SCHEMA::dbo TO terminal02; GRANT VIEW DEFINITION ON SCHEMA::dbo TO terminal02;
Zdeněk Neustupa