To read Environment variables in T-SQL, you can use the
xp_cmdshell extended stored procedure in SQL Server.
The following example shows how to read the
%windir% environment variable, which gives the Windows directory path on SQL Server using
DECLARE @windir nvarchar(255)
CREATE TABLE #Tmp
INSERT INTO #Tmp exec xp_cmdshell 'echo %windir%'
SET @windir = (SELECT TOP 1 EnvVar from #Tmp)
SELECT @windir as 'Windows Directory'
NOTE:To run this command, you need to be a member of the sysadmin fixed server. If you want others to be able to execute this command, you will have to explicitly grant them permission to execute the
xp_cmdshell stored procedure.
Find more information about this stored procedure at MSDN.