Retrieving the DATA folder installation path from MS SQL Server using T/SQL

This would be useful for creating databases using SQL scripts. The SQL query below returns the installation path of the DATA folder for the installed SQL Server.

SQL Script

DECLARE @device_directory NVARCHAR(520)

SELECT @device_directory = 
	SUBSTRING(filename, 1, CHARINDEX(N'master.mdf', LOWER(filename)) - 1)
FROM master.dbo.sysaltfiles 
WHERE dbid = 1 AND fileid = 1

print @device_directory

Output

C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\