Attach and Detach Database

-- You don't want to be in the database you are trying to detach
USE Master
GO

-- Optional step to drop all active connections and roll back their work
ALTER DATABASE DatabaseName
SET SINGLE_USER WITH ROLLBACK IMMEDIATE
GO

-- Perform the detach
EXEC sp_detach_db test
GO


CREATE DATABASE CORD_DB_1525
    ON (FILENAME = 'E:\External_HD\DATA\Test.mdf'), -- Main Data File .mdf
    (FILENAME = 'E:\External_HD\DATA\Test_log.ldf'), -- Log file .ldf
     (FILENAME = 'E:\External_HD\DATA\Test.ndf') -- Optional - any secondary data files
    FOR ATTACH
GO