Information Query related system functions and system variables (SQL Server)

of the current session.

function name	function
host_id	return the ID of the server-side computer
host_name	return the name of the server computer
db_id	ID of the returned Database ID
db_name	return database name
app_name	returns the application Program name
user_name	return the database user name based on the specified ID number
CURRENT_USER	return the name of the current user. This function is equivalent to user_name ()
system variable	variable information
@ language	return the name of the current language
@ servername	return the name of the local server running SQL server
@ version	return the version, processor architecture, generation date, and operating system of the current SQL Server Installation.
@ spid	the session ID of the current process is returned
@ trancount	Number of active transactions returned for the current connection
@ error	return the error code of the last executed Transact-SQL statement