How to get current instance name from T-SQL

Question

How can I get the SQL Server server and instance name of the current connection, using a T-SQL script?

Answer 1

I found this:

EXECUTE xp_regread
        @rootkey = 'HKEY_LOCAL_MACHINE',
        @key = 'SOFTWARE\Microsoft\Microsoft SQL Server',
        @value_name = 'InstalledInstances'

That will give you list of all instances installed in your server.

---

The ServerName property of the SERVERPROPERTY function and @@SERVERNAME return similar information. The ServerName property provides the Windows server and instance name that together make up the unique server instance. @@SERVERNAME provides the currently configured local server name.

And Microsoft example for current server is:

SELECT CONVERT(sysname, SERVERPROPERTY('servername'));

This scenario is useful when there are multiple instances of SQL Server installed on a Windows server, and the client must open another connection to the same instance used by the current connection.