Enumerate SQL Server Instances in C#, Using ODBC

Sample Image - C#SQLInfoEnumeratorDemo.jpg

Introduction

This article describes a C# class that utilises ODBC (SQLBrowseConnect) to obtain a list of SQL Servers on a network and returns an array of instances. If an instance is supplied with a valid username/password, then a list of all the databases on the instance is returned.

Background

I needed a way to obtain a list of SQL Server instances without using SQLDMO. I found a C++ implementation of the SQLBrowseConnect by Santosh Rao. This is a C# implementation.

Using the code

In order for the code to work, ODBC must be installed on your machine. Nearly all Microsoft Operating Systems have this installed. I have only tested this on Windows 2000 and XP. In order to use this, add a reference to the SQLEnumerator.cs file. The class is in the Moletrator.SQLDocumentor namespace and is SQLInfoEnumerator. The important work is done in the RetrieveInformation method. This calls the relevant ODBC commands passing in the relevant values. The important item is the value of inputParam. If this is blank then nothing is returned. When it contains a valid driver (DRIVER=SQL SERVER for MS SQL Server), it will check for all instances of this driver on the network returning a string value which is then parsed.

If this string is expanded to include a valid SQL Server instance and a valid username/password, then a list of all the databases on the server instance is returned. If the username/password are not valid then the a list of SQL Server instances is returned:

In order to get a list of SQL Server instances, create an instance of the class and call EnumerateSQLServers. The example below adds the list of SQL Servers to a list box SQLListBox.
```
SQLInfoEnumerator sie = new SQLInfoEnumerator();
SQLListBox.Items.AddRange(sie.EnumerateSQLServers());
```

To get a list of databases on a SQL Server instance, use the code below. The SQL Server instance is the selected instance from the list box populated in sample A. The username/password are entered by the user.

SQLInfoEnumerator sie = new SQLInfoEnumerator();
sie.SQLServer = listboxSQLServerInstances.SelectedItem.ToString(); 
sie.Username = textboxUserName.Text;
sie.Password = textboxPassword.Text;
SQLListBox.Items.AddRange(sie.EnumerateSQLServersDatabases());

The demo code contains a full GUI with an example on how to call each of the above methods.