I have an SQL Server (2008 R2) based (C# WinForms) application that predominantly runs on a local machine using a local installation of SQL Server 2008 R2. One problem I have is that if the user does not have a server instance running and tries to execute some commands or perform some operations, the queries are sent off to SQL Server and it takes an age to throw an SqlException telling me the requested instance is not started.
I have read the following question and associated answers, but these solutions are far from ideal. WMI seem very much over-kill and I do not want to have to include extra .dlls in my installation package for the software if it can be avoided.
I have also come accross the SqlDataSourceEnumerator Class documented here
// Retrieve the enumerator instance and then the data.
SqlDataSourceEnumerator instance = SqlDataSourceEnumerator.Instance;
System.Data.DataTable table = instance.GetDataSources();
which dumps the available connection into a DataTable. However, there seems to be inherent problems with returning all the available connections:
"All of the available servers may or may not be listed. The list can vary depending on
factors such as timeouts and network traffic. This can cause the list to be different
on two consecutive calls." - MSDN.
There has to be a set way of dealing with this problem. Say I have the following SqlConnection string:
Data Source=localhost;Initial Catalog=MyDB;Integrated Security=True;Connection Timeout = 0
what can I use as an efficient (this is crucial) check as to whether the selected instance (‘localhost’ [the default instance] or ‘SomeInstanceName’) is running?
Thanks for your time.
You can change the connection timeout to be a shorter period, but essentially, the only way it knows that a server isn’t there, is from a timeout.